from nmigen.cli import main
import sys
+from nmutil.singlepipe import ControlBase
+from soc.simple.core_data import FetchOutput, FetchInput
+
from nmigen.lib.coding import PriorityEncoder
from openpower.decoder.power_decoder import create_pdecode
from openpower.decoder.decode2execute1 import IssuerDecode2ToOperand
from openpower.decoder.decode2execute1 import Data
from openpower.decoder.power_enums import (MicrOp, SVP64PredInt, SVP64PredCR,
- SVP64PredMode)
+ SVP64PredMode)
from openpower.state import CoreState
-from openpower.consts import (CR, SVP64CROffs)
-from soc.experiment.testmem import TestMemory # test only for instructions
+from openpower.consts import (CR, SVP64CROffs, MSR)
+from soc.experiment.testmem import TestMemory # test only for instructions
from soc.regfile.regfiles import StateRegs, FastRegs
from soc.simple.core import NonProductionCore
from soc.config.test.test_loadstore import TestMemPspec
from soc.clock.select import ClockSelect
from soc.clock.dummypll import DummyPLL
from openpower.sv.svstate import SVSTATERec
-
+from soc.experiment.icache import ICache
from nmutil.util import rising_edge
+
def get_insn(f_instr_o, pc):
if f_instr_o.width == 32:
return f_instr_o
return f_instr_o.word_select(pc[2], 32)
# gets state input or reads from state regfile
-def state_get(m, core_rst, state_i, name, regfile, regnum):
+
+
+def state_get(m, res, core_rst, state_i, name, regfile, regnum):
comb = m.d.comb
sync = m.d.sync
- # read the PC
- res = Signal(64, reset_less=True, name=name)
+ # read the {insert state variable here}
res_ok_delay = Signal(name="%s_ok_delay" % name)
with m.If(~core_rst):
sync += res_ok_delay.eq(~state_i.ok)
# incoming override (start from pc_i)
comb += res.eq(state_i.data)
with m.Else():
- # otherwise read StateRegs regfile for PC...
- comb += regfile.ren.eq(1<<regnum)
+ # otherwise read StateRegs regfile for {insert state here}...
+ comb += regfile.ren.eq(1 << regnum)
# ... but on a 1-clock delay
with m.If(res_ok_delay):
- comb += res.eq(regfile.data_o)
- return res
+ comb += res.eq(regfile.o_data)
+
def get_predint(m, mask, name):
"""decode SVP64 predicate integer mask field to reg number and invert
comb += invert.eq(1)
return regread, invert, unary, all1s
+
def get_predcr(m, mask, name):
"""decode SVP64 predicate CR to reg number field and invert status
this is identical to _get_predcr in ISACaller
return idx, invert
-class TestIssuerInternal(Elaboratable):
- """TestIssuer - reads instructions from TestMemory and issues them
+class TestIssuerBase(Elaboratable):
+ """TestIssuerBase - common base class for Issuers
- efficiency and speed is not the main goal here: functional correctness
- and code clarity is. optimisations (which almost 100% interfere with
- easy understanding) come later.
+ takes care of power-on reset, peripherals, debug, DEC/TB,
+ and gets PC/MSR/SVSTATE from the State Regfile etc.
"""
+
def __init__(self, pspec):
+ # test if microwatt compatibility is to be enabled
+ self.microwatt_compat = (hasattr(pspec, "microwatt_compat") and
+ (pspec.microwatt_compat == True))
+ self.alt_reset = Signal(reset_less=True) # not connected yet (microwatt)
+ # test if fabric compatibility is to be enabled
+ self.fabric_compat = (hasattr(pspec, "fabric_compat") and
+ (pspec.fabric_compat == True))
+
+ if self.microwatt_compat or self.fabric_compat:
+
+ if hasattr(pspec, "microwatt_old"):
+ self.microwatt_old = pspec.microwatt_old
+ else:
+ self.microwatt_old = True # PLEASE DO NOT ALTER THIS
+
+ if hasattr(pspec, "microwatt_debug"):
+ self.microwatt_debug = pspec.microwatt_debug
+ else:
+ self.microwatt_debug = True # set to False when using an FPGA
+
# test is SVP64 is to be enabled
self.svp64_en = hasattr(pspec, "svp64") and (pspec.svp64 == True)
# and if regfiles are reduced
self.regreduce_en = (hasattr(pspec, "regreduce") and
- (pspec.regreduce == True))
+ (pspec.regreduce == True))
+
+ # and if overlap requested
+ self.allow_overlap = (hasattr(pspec, "allow_overlap") and
+ (pspec.allow_overlap == True))
+
+ # and get the core domain
+ self.core_domain = "coresync"
+ if (hasattr(pspec, "core_domain") and
+ isinstance(pspec.core_domain, str)):
+ self.core_domain = pspec.core_domain
# JTAG interface. add this right at the start because if it's
# added it *modifies* the pspec, by adding enable/disable signals
# for parts of the rest of the core
self.jtag_en = hasattr(pspec, "debug") and pspec.debug == 'jtag'
+ #self.dbg_domain = "sync" # sigh "dbgsunc" too problematic
+ self.dbg_domain = "dbgsync" # domain for DMI/JTAG clock
if self.jtag_en:
- # XXX MUST keep this up-to-date with litex, and
+ # XXX MUST keep this up-to-date with fabric, and
# soc-cocotb-sim, and err.. all needs sorting out, argh
subset = ['uart',
'mtwi',
'eint', 'gpio', 'mspi0',
# 'mspi1', - disabled for now
# 'pwm', 'sd0', - disabled for now
- 'sdr']
- self.jtag = JTAG(get_pinspecs(subset=subset))
+ 'sdr']
+ self.jtag = JTAG(get_pinspecs(subset=subset),
+ domain=self.dbg_domain)
# add signals to pspec to enable/disable icache and dcache
# (or data and intstruction wishbone if icache/dcache not included)
# https://bugs.libre-soc.org/show_bug.cgi?id=520
self.sram4k = []
for i in range(4):
self.sram4k.append(SPBlock512W64B8W(name="sram4k_%d" % i,
- features={'err'}))
+ # features={'err'}
+ ))
# add interrupt controller?
self.xics = hasattr(pspec, "xics") and pspec.xics == True
self.xics_icp = XICS_ICP()
self.xics_ics = XICS_ICS()
self.int_level_i = self.xics_ics.int_level_i
+ else:
+ self.ext_irq = Signal()
# add GPIO peripheral?
self.gpio = hasattr(pspec, "gpio") and pspec.gpio == True
# main instruction core. suitable for prototyping / demo only
self.core = core = NonProductionCore(pspec)
+ self.core_rst = ResetSignal(self.core_domain)
# instruction decoder. goes into Trap Record
- pdecode = create_pdecode()
- self.cur_state = CoreState("cur") # current state (MSR/PC/SVSTATE)
- self.pdecode2 = PowerDecode2(pdecode, state=self.cur_state,
+ #pdecode = create_pdecode()
+ self.cur_state = CoreState("cur") # current state (MSR/PC/SVSTATE)
+ self.pdecode2 = PowerDecode2(None, state=self.cur_state,
opkls=IssuerDecode2ToOperand,
svp64_en=self.svp64_en,
regreduce_en=self.regreduce_en)
+ pdecode = self.pdecode2.dec
+
if self.svp64_en:
- self.svp64 = SVP64PrefixDecoder() # for decoding SVP64 prefix
+ self.svp64 = SVP64PrefixDecoder() # for decoding SVP64 prefix
+
+ self.update_svstate = Signal() # set this if updating svstate
+ self.new_svstate = new_svstate = SVSTATERec("new_svstate")
# Test Instruction memory
+ if hasattr(core, "icache"):
+ # XXX BLECH! use pspec to transfer the I-Cache to ConfigFetchUnit
+ # truly dreadful. needs a huge reorg.
+ pspec.icache = core.icache
self.imem = ConfigFetchUnit(pspec).fu
# DMI interface
self.dbg = CoreDebug()
+ self.dbg_rst_i = Signal(reset_less=True)
# instruction go/monitor
self.pc_o = Signal(64, reset_less=True)
- self.pc_i = Data(64, "pc_i") # set "ok" to indicate "please change me"
- self.svstate_i = Data(32, "svstate_i") # ditto
- self.core_bigendian_i = Signal() # TODO: set based on MSR.LE
+ self.pc_i = Data(64, "pc_i") # set "ok" to indicate "please change me"
+ self.msr_i = Data(64, "msr_i") # set "ok" to indicate "please change me"
+ self.svstate_i = Data(64, "svstate_i") # ditto
+ self.core_bigendian_i = Signal() # TODO: set based on MSR.LE
self.busy_o = Signal(reset_less=True)
self.memerr_o = Signal(reset_less=True)
# STATE regfile read /write ports for PC, MSR, SVSTATE
staterf = self.core.regs.rf['state']
- self.state_r_pc = staterf.r_ports['cia'] # PC rd
- self.state_w_pc = staterf.w_ports['d_wr1'] # PC wr
- self.state_r_msr = staterf.r_ports['msr'] # MSR rd
- self.state_r_sv = staterf.r_ports['sv'] # SVSTATE rd
- self.state_w_sv = staterf.w_ports['sv'] # SVSTATE wr
+ self.state_r_msr = staterf.r_ports['msr'] # MSR rd
+ self.state_r_pc = staterf.r_ports['cia'] # PC rd
+ self.state_r_sv = staterf.r_ports['sv'] # SVSTATE rd
+
+ self.state_w_msr = staterf.w_ports['d_wr2'] # MSR wr
+ self.state_w_pc = staterf.w_ports['d_wr1'] # PC wr
+ self.state_w_sv = staterf.w_ports['sv'] # SVSTATE wr
# DMI interface access
intrf = self.core.regs.rf['int']
+ fastrf = self.core.regs.rf['fast']
crrf = self.core.regs.rf['cr']
xerrf = self.core.regs.rf['xer']
- self.int_r = intrf.r_ports['dmi'] # INT read
- self.cr_r = crrf.r_ports['full_cr_dbg'] # CR read
- self.xer_r = xerrf.r_ports['full_xer'] # XER read
+ self.int_r = intrf.r_ports['dmi'] # INT DMI read
+ self.cr_r = crrf.r_ports['full_cr_dbg'] # CR DMI read
+ self.xer_r = xerrf.r_ports['full_xer'] # XER DMI read
+ self.fast_r = fastrf.r_ports['dmi'] # FAST DMI read
if self.svp64_en:
# for predication
- self.int_pred = intrf.r_ports['pred'] # INT predicate read
- self.cr_pred = crrf.r_ports['cr_pred'] # CR predicate read
+ self.int_pred = intrf.r_ports['pred'] # INT predicate read
+ self.cr_pred = crrf.r_ports['cr_pred'] # CR predicate read
# hack method of keeping an eye on whether branch/trap set the PC
self.state_nia = self.core.regs.rf['state'].w_ports['nia']
self.state_nia.wen.name = 'state_nia_wen'
+ # and whether SPR pipeline sets DEC or TB (fu/spr/main_stage.py)
+ self.state_spr = self.core.regs.rf['state'].w_ports['state1']
# pulse to synchronize the simulator at instruction end
self.insn_done = Signal()
+ # indicate any instruction still outstanding, in execution
+ self.any_busy = Signal()
+
if self.svp64_en:
# store copies of predicate masks
self.srcmask = Signal(64)
self.dstmask = Signal(64)
- def fetch_fsm(self, m, core, pc, svstate, nia, is_svp64_mode,
- fetch_pc_ready_o, fetch_pc_valid_i,
- fetch_insn_valid_o, fetch_insn_ready_i):
+ # sigh, the wishbone addresses are not wishbone-compliant
+ # in old versions of microwatt, tplaten_3d_game is a new one
+ if self.microwatt_compat or self.fabric_compat:
+ self.ibus_adr = Signal(32, name='wishbone_insn_out.adr')
+ self.dbus_adr = Signal(32, name='wishbone_data_out.adr')
+
+ # add an output of the PC and instruction, and whether it was requested
+ # this is for verilator debug purposes
+ if self.microwatt_compat or self.fabric_compat:
+ self.nia = Signal(64)
+ self.msr_o = Signal(64)
+ self.nia_req = Signal(1)
+ self.insn = Signal(32)
+ self.ldst_req = Signal(1)
+ self.ldst_addr = Signal(1)
+
+ # for pausing dec/tb during an SPR pipeline event, this
+ # ensures that an SPR write (mtspr) to TB or DEC does not
+ # get overwritten by the DEC/TB FSM
+ self.pause_dec_tb = Signal()
+
+ def setup_peripherals(self, m):
+ comb, sync = m.d.comb, m.d.sync
+
+ # okaaaay so the debug module must be in coresync clock domain
+ # but NOT its reset signal. to cope with this, set every single
+ # submodule explicitly in coresync domain, debug and JTAG
+ # in their own one but using *external* reset.
+ csd = DomainRenamer(self.core_domain)
+ dbd = DomainRenamer(self.dbg_domain)
+
+ if self.microwatt_compat or self.fabric_compat:
+ m.submodules.core = core = self.core
+ else:
+ m.submodules.core = core = csd(self.core)
+
+ # this _so_ needs sorting out. ICache is added down inside
+ # LoadStore1 and is already a submodule of LoadStore1
+ if not isinstance(self.imem, ICache):
+ m.submodules.imem = imem = csd(self.imem)
+
+ # set up JTAG Debug Module (in correct domain)
+ m.submodules.dbg = dbg = dbd(self.dbg)
+ if self.jtag_en:
+ m.submodules.jtag = jtag = dbd(self.jtag)
+ # TODO: UART2GDB mux, here, from external pin
+ # see https://bugs.libre-soc.org/show_bug.cgi?id=499
+ sync += dbg.dmi.connect_to(jtag.dmi)
+
+ # fixup the clocks in microwatt-compat mode (but leave resets alone
+ # so that microwatt soc.vhdl can pull a reset on the core or DMI
+ # can do it, just like in TestIssuer)
+ if self.microwatt_compat or self.fabric_compat:
+ intclk = ClockSignal(self.core_domain)
+ dbgclk = ClockSignal(self.dbg_domain)
+ if self.core_domain != 'sync':
+ comb += intclk.eq(ClockSignal())
+ if self.dbg_domain != 'sync':
+ comb += dbgclk.eq(ClockSignal())
+
+ # if using old version of microwatt
+ # drop the first 3 bits of the incoming wishbone addresses
+ if self.microwatt_compat or self.fabric_compat:
+ ibus = self.imem.ibus
+ dbus = self.core.l0.cmpi.wb_bus()
+ if self.microwatt_old:
+ comb += self.ibus_adr.eq(Cat(Const(0, 3), ibus.adr))
+ comb += self.dbus_adr.eq(Cat(Const(0, 3), dbus.adr))
+ else:
+ comb += self.ibus_adr.eq(ibus.adr)
+ comb += self.dbus_adr.eq(dbus.adr)
+ if self.microwatt_debug:
+ # microwatt verilator debug purposes
+ pi = self.core.l0.cmpi.pi.pi
+ comb += self.ldst_req.eq(pi.addr_ok_o)
+ comb += self.ldst_addr.eq(pi.addr)
+
+ cur_state = self.cur_state
+
+ # 4x 4k SRAM blocks. these simply "exist", they get routed in fabric
+ if self.sram4x4k:
+ for i, sram in enumerate(self.sram4k):
+ m.submodules["sram4k_%d" % i] = csd(sram)
+ comb += sram.enable.eq(self.wb_sram_en)
+
+ # XICS interrupt handler
+ if self.xics:
+ m.submodules.xics_icp = icp = csd(self.xics_icp)
+ m.submodules.xics_ics = ics = csd(self.xics_ics)
+ comb += icp.ics_i.eq(ics.icp_o) # connect ICS to ICP
+ sync += cur_state.eint.eq(icp.core_irq_o) # connect ICP to core
+ else:
+ sync += cur_state.eint.eq(self.ext_irq) # connect externally
+
+ # GPIO test peripheral
+ if self.gpio:
+ m.submodules.simple_gpio = simple_gpio = csd(self.simple_gpio)
+
+ # connect one GPIO output to ICS bit 15 (like in microwatt soc.vhdl)
+ # XXX causes fabric ECP5 test to get wrong idea about input and output
+ # (but works with verilator sim *sigh*)
+ # if self.gpio and self.xics:
+ # comb += self.int_level_i[15].eq(simple_gpio.gpio_o[0])
+
+ # instruction decoder
+ pdecode = create_pdecode()
+ m.submodules.dec2 = pdecode2 = csd(self.pdecode2)
+ if self.svp64_en:
+ m.submodules.svp64 = svp64 = csd(self.svp64)
+
+ # clock delay power-on reset
+ cd_por = ClockDomain(reset_less=True)
+ cd_sync = ClockDomain()
+ m.domains += cd_por, cd_sync
+ core_sync = ClockDomain(self.core_domain)
+ if self.core_domain != "sync":
+ m.domains += core_sync
+ if self.dbg_domain != "sync":
+ dbg_sync = ClockDomain(self.dbg_domain)
+ m.domains += dbg_sync
+
+ # create a delay, but remember it is in the power-on-reset clock domain!
+ ti_rst = Signal(reset_less=True)
+ delay = Signal(range(4), reset=3)
+ stop_delay = Signal(range(16), reset=5)
+ with m.If(delay != 0):
+ m.d.por += delay.eq(delay - 1) # decrement... in POR domain!
+ with m.If(stop_delay != 0):
+ m.d.por += stop_delay.eq(stop_delay - 1) # likewise
+ comb += cd_por.clk.eq(ClockSignal())
+
+ # power-on reset delay
+ core_rst = ResetSignal(self.core_domain)
+ if self.core_domain != "sync":
+ comb += ti_rst.eq(delay != 0 | dbg.core_rst_o | ResetSignal())
+ comb += core_rst.eq(ti_rst)
+ else:
+ with m.If(delay != 0 | dbg.core_rst_o):
+ comb += core_rst.eq(1)
+ with m.If(stop_delay != 0):
+ # run DMI core-stop as well but on an extra couple of cycles
+ comb += dbg.core_stopped_i.eq(1)
+
+ # connect external reset signal to DMI Reset
+ if self.dbg_domain != "sync":
+ dbg_rst = ResetSignal(self.dbg_domain)
+ comb += dbg_rst.eq(self.dbg_rst_i)
+
+ # busy/halted signals from core
+ core_busy_o = ~core.p.o_ready | core.n.o_data.busy_o # core is busy
+ comb += self.busy_o.eq(core_busy_o)
+ comb += pdecode2.dec.bigendian.eq(self.core_bigendian_i)
+
+ # temporary hack: says "go" immediately for both address gen and ST
+ # XXX: st.go_i is set to 1 cycle delay to reduce combinatorial chains
+ l0 = core.l0
+ ldst = core.fus.fus['ldst0']
+ st_go_edge = rising_edge(m, ldst.st.rel_o)
+ # link addr-go direct to rel
+ m.d.comb += ldst.ad.go_i.eq(ldst.ad.rel_o)
+ m.d.sync += ldst.st.go_i.eq(st_go_edge) # link store-go to rising rel
+
+ def do_dmi(self, m, dbg):
+ """deals with DMI debug requests
+
+ currently only provides read requests for the INT regfile, CR and XER
+ it will later also deal with *writing* to these regfiles.
+ """
+ comb = m.d.comb
+ sync = m.d.sync
+ dmi, d_reg, d_cr, d_xer, = dbg.dmi, dbg.d_gpr, dbg.d_cr, dbg.d_xer
+ d_fast = dbg.d_fast
+ intrf = self.core.regs.rf['int']
+ fastrf = self.core.regs.rf['fast']
+
+ with m.If(d_reg.req): # request for regfile access being made
+ # TODO: error-check this
+ # XXX should this be combinatorial? sync better?
+ if intrf.unary:
+ comb += self.int_r.ren.eq(1 << d_reg.addr)
+ else:
+ comb += self.int_r.addr.eq(d_reg.addr)
+ comb += self.int_r.ren.eq(1)
+ d_reg_delay = Signal()
+ sync += d_reg_delay.eq(d_reg.req)
+ with m.If(d_reg_delay):
+ # data arrives one clock later
+ comb += d_reg.data.eq(self.int_r.o_data)
+ comb += d_reg.ack.eq(1)
+
+ # fast regfile
+ with m.If(d_fast.req): # request for regfile access being made
+ if fastrf.unary:
+ comb += self.fast_r.ren.eq(1 << d_fast.addr)
+ else:
+ comb += self.fast_r.addr.eq(d_fast.addr)
+ comb += self.fast_r.ren.eq(1)
+ d_fast_delay = Signal()
+ sync += d_fast_delay.eq(d_fast.req)
+ with m.If(d_fast_delay):
+ # data arrives one clock later
+ comb += d_fast.data.eq(self.fast_r.o_data)
+ comb += d_fast.ack.eq(1)
+
+ # sigh same thing for CR debug
+ with m.If(d_cr.req): # request for regfile access being made
+ comb += self.cr_r.ren.eq(0b11111111) # enable all
+ d_cr_delay = Signal()
+ sync += d_cr_delay.eq(d_cr.req)
+ with m.If(d_cr_delay):
+ # data arrives one clock later
+ comb += d_cr.data.eq(self.cr_r.o_data)
+ comb += d_cr.ack.eq(1)
+
+ # aaand XER...
+ with m.If(d_xer.req): # request for regfile access being made
+ comb += self.xer_r.ren.eq(0b111111) # enable all
+ d_xer_delay = Signal()
+ sync += d_xer_delay.eq(d_xer.req)
+ with m.If(d_xer_delay):
+ # data arrives one clock later
+ comb += d_xer.data.eq(self.xer_r.o_data)
+ comb += d_xer.ack.eq(1)
+
+ def tb_dec_fsm(self, m, spr_dec):
+ """tb_dec_fsm
+
+ this is a FSM for updating either dec or tb. it runs alternately
+ DEC, TB, DEC, TB. note that SPR pipeline could have written a new
+ value to DEC, however the regfile has "passthrough" on it so this
+ *should* be ok.
+
+ see v3.0B p1097-1099 for Timer Resource and p1065 and p1076
+ """
+
+ comb, sync = m.d.comb, m.d.sync
+ state_rf = self.core.regs.rf['state']
+ state_r_dectb = state_rf.r_ports['issue'] # DEC/TB
+ state_w_dectb = state_rf.w_ports['issue'] # DEC/TB
+
+
+ with m.FSM() as fsm:
+
+ # initiates read of current DEC
+ with m.State("DEC_READ"):
+ comb += state_r_dectb.ren.eq(1<<StateRegs.DEC)
+ with m.If(~self.pause_dec_tb):
+ m.next = "DEC_WRITE"
+
+ # waits for DEC read to arrive (1 cycle), updates with new value
+ # respects if dec/tb writing has been paused
+ with m.State("DEC_WRITE"):
+ with m.If(self.pause_dec_tb):
+ # if paused, return to reading
+ m.next = "DEC_READ"
+ with m.Else():
+ new_dec = Signal(64)
+ # TODO: MSR.LPCR 32-bit decrement mode
+ comb += new_dec.eq(state_r_dectb.o_data - 1)
+ comb += state_w_dectb.wen.eq(1<<StateRegs.DEC)
+ comb += state_w_dectb.i_data.eq(new_dec)
+ # copy to cur_state for decoder, for an interrupt
+ sync += spr_dec.eq(new_dec)
+ m.next = "TB_READ"
+
+ # initiates read of current TB
+ with m.State("TB_READ"):
+ comb += state_r_dectb.ren.eq(1<<StateRegs.TB)
+ with m.If(~self.pause_dec_tb):
+ m.next = "TB_WRITE"
+
+ # waits for read TB to arrive, initiates write of current TB
+ # respects if dec/tb writing has been paused
+ with m.State("TB_WRITE"):
+ with m.If(self.pause_dec_tb):
+ # if paused, return to reading
+ m.next = "TB_READ"
+ with m.Else():
+ new_tb = Signal(64)
+ comb += new_tb.eq(state_r_dectb.o_data + 1)
+ comb += state_w_dectb.wen.eq(1<<StateRegs.TB)
+ comb += state_w_dectb.i_data.eq(new_tb)
+ m.next = "DEC_READ"
+
+ return m
+
+ def elaborate(self, platform):
+ m = Module()
+ # convenience
+ comb, sync = m.d.comb, m.d.sync
+ cur_state = self.cur_state
+ pdecode2 = self.pdecode2
+ dbg = self.dbg
+
+ # set up peripherals and core
+ core_rst = self.core_rst
+ self.setup_peripherals(m)
+
+ # reset current state if core reset requested
+ with m.If(core_rst):
+ m.d.sync += self.cur_state.eq(0)
+ # and, sigh, set configured values, which are also done in regfile
+ # XXX ??? what the hell is the shift for??
+ m.d.sync += self.cur_state.pc.eq(self.core.pc_at_reset)
+ m.d.sync += self.cur_state.msr.eq(self.core.msr_at_reset)
+
+ # check halted condition: requested PC to execute matches DMI stop addr
+ # and immediately stop. address of 0xffff_ffff_ffff_ffff can never
+ # match
+ halted = Signal()
+ comb += halted.eq(dbg.stop_addr_o == dbg.state.pc)
+ with m.If(halted):
+ comb += dbg.core_stopped_i.eq(1)
+ comb += dbg.terminate_i.eq(1)
+
+ # PC and instruction from I-Memory
+ comb += self.pc_o.eq(cur_state.pc)
+ self.pc_changed = Signal() # note write to PC
+ self.msr_changed = Signal() # note write to MSR
+ self.sv_changed = Signal() # note write to SVSTATE
+
+ # read state either from incoming override or from regfile
+ state = CoreState("get") # current state (MSR/PC/SVSTATE)
+ state_get(m, state.msr, core_rst, self.msr_i,
+ "msr", # read MSR
+ self.state_r_msr, StateRegs.MSR)
+ state_get(m, state.pc, core_rst, self.pc_i,
+ "pc", # read PC
+ self.state_r_pc, StateRegs.PC)
+ state_get(m, state.svstate, core_rst, self.svstate_i,
+ "svstate", # read SVSTATE
+ self.state_r_sv, StateRegs.SVSTATE)
+
+ # don't write pc every cycle
+ comb += self.state_w_pc.wen.eq(0)
+ comb += self.state_w_pc.i_data.eq(0)
+
+ # connect up debug state. note "combinatorially same" below,
+ # this is a bit naff, passing state over in the dbg class, but
+ # because it is combinatorial it achieves the desired goal
+ comb += dbg.state.eq(state)
+
+ # this bit doesn't have to be in the FSM: connect up to read
+ # regfiles on demand from DMI
+ self.do_dmi(m, dbg)
+
+ # DEC and TB inc/dec FSM. copy of DEC is put into CoreState,
+ # (which uses that in PowerDecoder2 to raise 0x900 exception)
+ self.tb_dec_fsm(m, cur_state.dec)
+
+ # while stopped, allow updating the MSR, PC and SVSTATE.
+ # these are mainly for debugging purposes (including DMI/JTAG)
+ with m.If(dbg.core_stopped_i):
+ with m.If(self.pc_i.ok):
+ comb += self.state_w_pc.wen.eq(1 << StateRegs.PC)
+ comb += self.state_w_pc.i_data.eq(self.pc_i.data)
+ sync += self.pc_changed.eq(1)
+ with m.If(self.msr_i.ok):
+ comb += self.state_w_msr.wen.eq(1 << StateRegs.MSR)
+ comb += self.state_w_msr.i_data.eq(self.msr_i.data)
+ sync += self.msr_changed.eq(1)
+ with m.If(self.svstate_i.ok | self.update_svstate):
+ with m.If(self.svstate_i.ok): # over-ride from external source
+ comb += self.new_svstate.eq(self.svstate_i.data)
+ comb += self.state_w_sv.wen.eq(1 << StateRegs.SVSTATE)
+ comb += self.state_w_sv.i_data.eq(self.new_svstate)
+ sync += self.sv_changed.eq(1)
+
+ # start renaming some of the ports to match microwatt
+ if self.microwatt_compat or self.fabric_compat:
+ self.core.o.core_terminate_o.name = "terminated_out"
+ # names of DMI interface
+ self.dbg.dmi.addr_i.name = 'dmi_addr'
+ self.dbg.dmi.din.name = 'dmi_din'
+ self.dbg.dmi.dout.name = 'dmi_dout'
+ self.dbg.dmi.req_i.name = 'dmi_req'
+ self.dbg.dmi.we_i.name = 'dmi_wr'
+ self.dbg.dmi.ack_o.name = 'dmi_ack'
+ # wishbone instruction bus
+ ibus = self.imem.ibus
+ if self.microwatt_compat:
+ ibus.adr.name = 'wishbone_insn_out.adr'
+ ibus.dat_w.name = 'wishbone_insn_out.dat'
+ ibus.sel.name = 'wishbone_insn_out.sel'
+ ibus.cyc.name = 'wishbone_insn_out.cyc'
+ ibus.stb.name = 'wishbone_insn_out.stb'
+ ibus.we.name = 'wishbone_insn_out.we'
+ ibus.dat_r.name = 'wishbone_insn_in.dat'
+ ibus.ack.name = 'wishbone_insn_in.ack'
+ ibus.stall.name = 'wishbone_insn_in.stall'
+ # wishbone data bus
+ dbus = self.core.l0.cmpi.wb_bus()
+ if self.microwatt_compat:
+ dbus.adr.name = 'wishbone_data_out.adr'
+ dbus.dat_w.name = 'wishbone_data_out.dat'
+ dbus.sel.name = 'wishbone_data_out.sel'
+ dbus.cyc.name = 'wishbone_data_out.cyc'
+ dbus.stb.name = 'wishbone_data_out.stb'
+ dbus.we.name = 'wishbone_data_out.we'
+ dbus.dat_r.name = 'wishbone_data_in.dat'
+ dbus.ack.name = 'wishbone_data_in.ack'
+ dbus.stall.name = 'wishbone_data_in.stall'
+
+ return m
+
+ def __iter__(self):
+ yield from self.pc_i.ports()
+ yield from self.msr_i.ports()
+ yield self.pc_o
+ yield self.memerr_o
+ yield from self.core.ports()
+ yield from self.imem.ports()
+ yield self.core_bigendian_i
+ yield self.busy_o
+
+ def ports(self):
+ return list(self)
+
+ def external_ports(self):
+ if self.microwatt_compat or self.fabric_compat:
+ if self.fabric_compat:
+ ports = [self.core.o.core_terminate_o,
+ self.alt_reset, # not connected yet
+ self.nia, self.insn, self.nia_req, self.msr_o,
+ self.ldst_req, self.ldst_addr,
+ ClockSignal(),
+ ResetSignal(),
+ ]
+ else:
+ ports = [self.core.o.core_terminate_o,
+ self.ext_irq,
+ self.alt_reset, # not connected yet
+ self.nia, self.insn, self.nia_req, self.msr_o,
+ self.ldst_req, self.ldst_addr,
+ ClockSignal(),
+ ResetSignal(),
+ ]
+ ports += list(self.dbg.dmi.ports())
+ # for dbus/ibus microwatt, exclude err btw and cti
+ for name, sig in self.imem.ibus.fields.items():
+ if name not in ['err', 'bte', 'cti', 'adr']:
+ ports.append(sig)
+ for name, sig in self.core.l0.cmpi.wb_bus().fields.items():
+ if name not in ['err', 'bte', 'cti', 'adr']:
+ ports.append(sig)
+ # microwatt non-compliant with wishbone
+ ports.append(self.ibus_adr)
+ ports.append(self.dbus_adr)
+
+ if self.microwatt_compat:
+ # Ignore the remaining ports in microwatt compat mode
+ return ports
+
+ ports = self.pc_i.ports()
+ ports = self.msr_i.ports()
+ ports += [self.pc_o, self.memerr_o, self.core_bigendian_i, self.busy_o,
+ ]
+
+ if self.jtag_en:
+ ports += list(self.jtag.external_ports())
+ else:
+ # don't add DMI if JTAG is enabled
+ ports += list(self.dbg.dmi.ports())
+
+ ports += list(self.imem.ibus.fields.values())
+ ports += list(self.core.l0.cmpi.wb_bus().fields.values())
+
+ if self.sram4x4k:
+ for sram in self.sram4k:
+ ports += list(sram.bus.fields.values())
+
+ if self.xics:
+ ports += list(self.xics_icp.bus.fields.values())
+ ports += list(self.xics_ics.bus.fields.values())
+ ports.append(self.int_level_i)
+ else:
+ ports.append(self.ext_irq)
+
+ if self.gpio:
+ ports += list(self.simple_gpio.bus.fields.values())
+ ports.append(self.gpio_o)
+
+ return ports
+
+ def ports(self):
+ return list(self)
+
+
+class TestIssuerInternal(TestIssuerBase):
+ """TestIssuer - reads instructions from TestMemory and issues them
+
+ efficiency and speed is not the main goal here: functional correctness
+ and code clarity is. optimisations (which almost 100% interfere with
+ easy understanding) come later.
+ """
+
+ def fetch_fsm(self, m, dbg, core, core_rst, nia, is_svp64_mode,
+ fetch_pc_o_ready, fetch_pc_i_valid,
+ fetch_insn_o_valid, fetch_insn_i_ready):
"""fetch FSM
this FSM performs fetch of raw instruction data, partial-decodes
pdecode2 = self.pdecode2
cur_state = self.cur_state
dec_opcode_i = pdecode2.dec.raw_opcode_in # raw opcode
+ pc, msr, svstate = cur_state.pc, cur_state.msr, cur_state.svstate
- msr_read = Signal(reset=1)
+ # also note instruction fetch failed
+ if hasattr(core, "icache"):
+ fetch_failed = core.icache.i_out.fetch_failed
+ flush_needed = True
+ else:
+ fetch_failed = Const(0, 1)
+ flush_needed = False
+
+ # set priv / virt mode on I-Cache, sigh
+ if isinstance(self.imem, ICache):
+ comb += self.imem.i_in.priv_mode.eq(~msr[MSR.PR])
+ comb += self.imem.i_in.virt_mode.eq(msr[MSR.IR]) # Instr. Redir (VM)
with m.FSM(name='fetch_fsm'):
+ # allow fetch to not run at startup due to I-Cache reset not
+ # having time to settle. power-on-reset holds dbg.core_stopped_i
+ with m.State("PRE_IDLE"):
+ with m.If(~dbg.core_stopped_i & ~dbg.core_stop_o & ~core_rst):
+ m.next = "IDLE"
+
# waiting (zzz)
with m.State("IDLE"):
- comb += fetch_pc_ready_o.eq(1)
- with m.If(fetch_pc_valid_i):
+ # fetch allowed if not failed and stopped but not stepping
+ # (see dmi.py for how core_stop_o is generated)
+ with m.If(~fetch_failed & ~dbg.core_stop_o):
+ comb += fetch_pc_o_ready.eq(1)
+ with m.If(fetch_pc_i_valid & ~pdecode2.instr_fault
+ & ~dbg.core_stop_o):
# instruction allowed to go: start by reading the PC
# capture the PC and also drop it into Insn Memory
# we have joined a pair of combinatorial memory
# lookups together. this is Generally Bad.
comb += self.imem.a_pc_i.eq(pc)
- comb += self.imem.a_valid_i.eq(1)
- comb += self.imem.f_valid_i.eq(1)
- sync += cur_state.pc.eq(pc)
- sync += cur_state.svstate.eq(svstate) # and svstate
-
- # initiate read of MSR. arrives one clock later
- comb += self.state_r_msr.ren.eq(1 << StateRegs.MSR)
- sync += msr_read.eq(0)
-
+ comb += self.imem.a_i_valid.eq(1)
+ comb += self.imem.f_i_valid.eq(1)
m.next = "INSN_READ" # move to "wait for bus" phase
# dummy pause to find out why simulation is not keeping up
with m.State("INSN_READ"):
- # one cycle later, msr/sv read arrives. valid only once.
- with m.If(~msr_read):
- sync += msr_read.eq(1) # yeah don't read it again
- sync += cur_state.msr.eq(self.state_r_msr.data_o)
- with m.If(self.imem.f_busy_o): # zzz...
- # busy: stay in wait-read
- comb += self.imem.a_valid_i.eq(1)
- comb += self.imem.f_valid_i.eq(1)
+ # when using "single-step" mode, checking dbg.stopping_o
+ # prevents progress. allow fetch to proceed once started
+ stopping = Const(0)
+ #if self.allow_overlap:
+ # stopping = dbg.stopping_o
+ with m.If(stopping):
+ # stopping: jump back to idle
+ m.next = "IDLE"
with m.Else():
- # not busy: instruction fetched
- insn = get_insn(self.imem.f_instr_o, cur_state.pc)
- if self.svp64_en:
- svp64 = self.svp64
- # decode the SVP64 prefix, if any
- comb += svp64.raw_opcode_in.eq(insn)
- comb += svp64.bigendian.eq(self.core_bigendian_i)
- # pass the decoded prefix (if any) to PowerDecoder2
- sync += pdecode2.sv_rm.eq(svp64.svp64_rm)
- # remember whether this is a prefixed instruction, so
- # the FSM can readily loop when VL==0
- sync += is_svp64_mode.eq(svp64.is_svp64_mode)
- # calculate the address of the following instruction
- insn_size = Mux(svp64.is_svp64_mode, 8, 4)
- sync += nia.eq(cur_state.pc + insn_size)
- with m.If(~svp64.is_svp64_mode):
- # with no prefix, store the instruction
- # and hand it directly to the next FSM
+ with m.If(self.imem.f_busy_o &
+ ~pdecode2.instr_fault): # zzz...
+ # busy but not fetch failed: stay in wait-read
+ comb += self.imem.a_pc_i.eq(pc)
+ comb += self.imem.a_i_valid.eq(1)
+ comb += self.imem.f_i_valid.eq(1)
+ with m.Else():
+ # not busy (or fetch failed!): instruction fetched
+ # when fetch failed, the instruction gets ignored
+ # by the decoder
+ if hasattr(core, "icache"):
+ # blech, icache returns actual instruction
+ insn = self.imem.f_instr_o
+ else:
+ # but these return raw memory
+ insn = get_insn(self.imem.f_instr_o, cur_state.pc)
+ if self.svp64_en:
+ svp64 = self.svp64
+ # decode the SVP64 prefix, if any
+ comb += svp64.raw_opcode_in.eq(insn)
+ comb += svp64.bigendian.eq(self.core_bigendian_i)
+ # pass the decoded prefix (if any) to PowerDecoder2
+ sync += pdecode2.sv_rm.eq(svp64.svp64_rm)
+ sync += pdecode2.is_svp64_mode.eq(is_svp64_mode)
+ # remember whether this is a prefixed instruction,
+ # so the FSM can readily loop when VL==0
+ sync += is_svp64_mode.eq(svp64.is_svp64_mode)
+ # calculate the address of the following instruction
+ insn_size = Mux(svp64.is_svp64_mode, 8, 4)
+ sync += nia.eq(cur_state.pc + insn_size)
+ with m.If(~svp64.is_svp64_mode):
+ # with no prefix, store the instruction
+ # and hand it directly to the next FSM
+ sync += dec_opcode_i.eq(insn)
+ m.next = "INSN_READY"
+ with m.Else():
+ # fetch the rest of the instruction from memory
+ comb += self.imem.a_pc_i.eq(cur_state.pc + 4)
+ comb += self.imem.a_i_valid.eq(1)
+ comb += self.imem.f_i_valid.eq(1)
+ m.next = "INSN_READ2"
+ else:
+ # not SVP64 - 32-bit only
+ sync += nia.eq(cur_state.pc + 4)
sync += dec_opcode_i.eq(insn)
+ if self.microwatt_compat or self.fabric_compat:
+ # for verilator debug purposes
+ comb += self.insn.eq(insn)
+ comb += self.nia.eq(cur_state.pc)
+ comb += self.msr_o.eq(cur_state.msr)
+ comb += self.nia_req.eq(1)
m.next = "INSN_READY"
- with m.Else():
- # fetch the rest of the instruction from memory
- comb += self.imem.a_pc_i.eq(cur_state.pc + 4)
- comb += self.imem.a_valid_i.eq(1)
- comb += self.imem.f_valid_i.eq(1)
- m.next = "INSN_READ2"
- else:
- # not SVP64 - 32-bit only
- sync += nia.eq(cur_state.pc + 4)
- sync += dec_opcode_i.eq(insn)
- m.next = "INSN_READY"
with m.State("INSN_READ2"):
with m.If(self.imem.f_busy_o): # zzz...
# busy: stay in wait-read
- comb += self.imem.a_valid_i.eq(1)
- comb += self.imem.f_valid_i.eq(1)
+ comb += self.imem.a_i_valid.eq(1)
+ comb += self.imem.f_i_valid.eq(1)
with m.Else():
# not busy: instruction fetched
- insn = get_insn(self.imem.f_instr_o, cur_state.pc+4)
+ if hasattr(core, "icache"):
+ # blech, icache returns actual instruction
+ insn = self.imem.f_instr_o
+ else:
+ insn = get_insn(self.imem.f_instr_o, cur_state.pc+4)
sync += dec_opcode_i.eq(insn)
m.next = "INSN_READY"
# TODO: probably can start looking at pdecode2.rm_dec
with m.State("INSN_READY"):
# hand over the instruction, to be decoded
- comb += fetch_insn_valid_o.eq(1)
- with m.If(fetch_insn_ready_i):
+ comb += fetch_insn_o_valid.eq(1)
+ with m.If(fetch_insn_i_ready):
m.next = "IDLE"
+
def fetch_predicate_fsm(self, m,
- pred_insn_valid_i, pred_insn_ready_o,
- pred_mask_valid_o, pred_mask_ready_i):
+ pred_insn_i_valid, pred_insn_o_ready,
+ pred_mask_o_valid, pred_mask_i_ready):
"""fetch_predicate_fsm - obtains (constructs in the case of CR)
src/dest predicate masks
comb = m.d.comb
sync = m.d.sync
pdecode2 = self.pdecode2
- rm_dec = pdecode2.rm_dec # SVP64RMModeDecode
+ rm_dec = pdecode2.rm_dec # SVP64RMModeDecode
predmode = rm_dec.predmode
srcpred, dstpred = rm_dec.srcpred, rm_dec.dstpred
cr_pred, int_pred = self.cr_pred, self.int_pred # read regfiles
with m.FSM(name="fetch_predicate"):
with m.State("FETCH_PRED_IDLE"):
- comb += pred_insn_ready_o.eq(1)
- with m.If(pred_insn_valid_i):
+ comb += pred_insn_o_ready.eq(1)
+ with m.If(pred_insn_i_valid):
with m.If(predmode == SVP64PredMode.INT):
# skip fetching destination mask register, when zero
with m.If(dall1s):
with m.If(dunary):
# set selected mask bit for 1<<r3 mode
dst_shift = Signal(range(64))
- comb += dst_shift.eq(self.int_pred.data_o & 0b111111)
+ comb += dst_shift.eq(self.int_pred.o_data & 0b111111)
sync += new_dstmask.eq(1 << dst_shift)
with m.Else():
# invert mask if requested
- sync += new_dstmask.eq(self.int_pred.data_o ^ inv)
+ sync += new_dstmask.eq(self.int_pred.o_data ^ inv)
# skip fetching source mask register, when zero
with m.If(sall1s):
sync += new_srcmask.eq(-1)
with m.If(sunary):
# set selected mask bit for 1<<r3 mode
src_shift = Signal(range(64))
- comb += src_shift.eq(self.int_pred.data_o & 0b111111)
+ comb += src_shift.eq(self.int_pred.o_data & 0b111111)
sync += new_srcmask.eq(1 << src_shift)
with m.Else():
# invert mask if requested
- sync += new_srcmask.eq(self.int_pred.data_o ^ inv)
+ sync += new_srcmask.eq(self.int_pred.o_data ^ inv)
m.next = "FETCH_PRED_SHIFT_MASK"
# fetch masks from the CR register file
cr_field = Signal(4)
scr_bit = Signal()
dcr_bit = Signal()
- comb += cr_field.eq(cr_pred.data_o)
- comb += scr_bit.eq(cr_field.bit_select(sidx, 1) ^ scrinvert)
- comb += dcr_bit.eq(cr_field.bit_select(didx, 1) ^ dcrinvert)
+ comb += cr_field.eq(cr_pred.o_data)
+ comb += scr_bit.eq(cr_field.bit_select(sidx, 1)
+ ^ scrinvert)
+ comb += dcr_bit.eq(cr_field.bit_select(didx, 1)
+ ^ dcrinvert)
# set the corresponding mask bit
bit_to_set = Signal.like(self.srcmask)
comb += bit_to_set.eq(1 << cur_cr_idx)
m.next = "FETCH_PRED_DONE"
with m.State("FETCH_PRED_DONE"):
- comb += pred_mask_valid_o.eq(1)
- with m.If(pred_mask_ready_i):
+ comb += pred_mask_o_valid.eq(1)
+ with m.If(pred_mask_i_ready):
m.next = "FETCH_PRED_IDLE"
- def issue_fsm(self, m, core, pc_changed, sv_changed, nia,
+ def issue_fsm(self, m, core, nia,
dbg, core_rst, is_svp64_mode,
- fetch_pc_ready_o, fetch_pc_valid_i,
- fetch_insn_valid_o, fetch_insn_ready_i,
- pred_insn_valid_i, pred_insn_ready_o,
- pred_mask_valid_o, pred_mask_ready_i,
- exec_insn_valid_i, exec_insn_ready_o,
- exec_pc_valid_o, exec_pc_ready_i):
+ fetch_pc_o_ready, fetch_pc_i_valid,
+ fetch_insn_o_valid, fetch_insn_i_ready,
+ pred_insn_i_valid, pred_insn_o_ready,
+ pred_mask_o_valid, pred_mask_i_ready,
+ exec_insn_i_valid, exec_insn_o_ready,
+ exec_pc_o_valid, exec_pc_i_ready):
"""issue FSM
decode / issue FSM. this interacts with the "fetch" FSM
sync = m.d.sync
pdecode2 = self.pdecode2
cur_state = self.cur_state
+ new_svstate = self.new_svstate
# temporaries
- dec_opcode_i = pdecode2.dec.raw_opcode_in # raw opcode
+ dec_opcode_i = pdecode2.dec.raw_opcode_in # raw opcode
# for updating svstate (things like srcstep etc.)
- update_svstate = Signal() # set this (below) if updating
- new_svstate = SVSTATERec("new_svstate")
comb += new_svstate.eq(cur_state.svstate)
# precalculate srcstep+1 and dststep+1
# note if an exception happened. in a pipelined or OoO design
# this needs to be accompanied by "shadowing" (or stalling)
- el = []
- for exc in core.fus.excs.values():
- el.append(exc.happened)
- exc_happened = Signal()
- if len(el) > 0: # at least one exception
- comb += exc_happened.eq(Cat(*el).bool())
+ exc_happened = self.core.o.exc_happened
+ # also note instruction fetch failed
+ if hasattr(core, "icache"):
+ fetch_failed = core.icache.i_out.fetch_failed
+ flush_needed = True
+ # set to fault in decoder
+ # update (highest priority) instruction fault
+ rising_fetch_failed = rising_edge(m, fetch_failed)
+ with m.If(rising_fetch_failed):
+ sync += pdecode2.instr_fault.eq(1)
+ else:
+ fetch_failed = Const(0, 1)
+ flush_needed = False
+
+ sync += fetch_pc_i_valid.eq(0)
with m.FSM(name="issue_fsm"):
+ with m.State("PRE_IDLE"):
+ with m.If(~dbg.core_stop_o & ~core_rst):
+ m.next = "ISSUE_START"
+
# sync with the "fetch" phase which is reading the instruction
# at this point, there is no instruction running, that
# could inadvertently update the PC.
with m.State("ISSUE_START"):
+ # reset instruction fault
+ sync += pdecode2.instr_fault.eq(0)
# wait on "core stop" release, before next fetch
# need to do this here, in case we are in a VL==0 loop
with m.If(~dbg.core_stop_o & ~core_rst):
- comb += fetch_pc_valid_i.eq(1) # tell fetch to start
- with m.If(fetch_pc_ready_o): # fetch acknowledged us
+ sync += fetch_pc_i_valid.eq(1) # tell fetch to start
+ sync += cur_state.pc.eq(dbg.state.pc)
+ sync += cur_state.svstate.eq(dbg.state.svstate)
+ sync += cur_state.msr.eq(dbg.state.msr)
+ with m.If(fetch_pc_o_ready): # fetch acknowledged us
m.next = "INSN_WAIT"
with m.Else():
# tell core it's stopped, and acknowledge debug handshake
comb += dbg.core_stopped_i.eq(1)
- # while stopped, allow updating the PC and SVSTATE
- with m.If(self.pc_i.ok):
- comb += self.state_w_pc.wen.eq(1 << StateRegs.PC)
- comb += self.state_w_pc.data_i.eq(self.pc_i.data)
- sync += pc_changed.eq(1)
+ # while stopped, allow updating SVSTATE
with m.If(self.svstate_i.ok):
comb += new_svstate.eq(self.svstate_i.data)
- comb += update_svstate.eq(1)
- sync += sv_changed.eq(1)
+ comb += self.update_svstate.eq(1)
+ sync += self.sv_changed.eq(1)
# wait for an instruction to arrive from Fetch
with m.State("INSN_WAIT"):
- comb += fetch_insn_ready_i.eq(1)
- with m.If(fetch_insn_valid_o):
- # loop into ISSUE_START if it's a SVP64 instruction
- # and VL == 0. this because VL==0 is a for-loop
- # from 0 to 0 i.e. always, always a NOP.
- cur_vl = cur_state.svstate.vl
- with m.If(is_svp64_mode & (cur_vl == 0)):
- # update the PC before fetching the next instruction
- # since we are in a VL==0 loop, no instruction was
- # executed that we could be overwriting
- comb += self.state_w_pc.wen.eq(1 << StateRegs.PC)
- comb += self.state_w_pc.data_i.eq(nia)
- comb += self.insn_done.eq(1)
- m.next = "ISSUE_START"
- with m.Else():
- if self.svp64_en:
- m.next = "PRED_START" # start fetching predicate
- else:
- m.next = "DECODE_SV" # skip predication
+ # when using "single-step" mode, checking dbg.stopping_o
+ # prevents progress. allow issue to proceed once started
+ stopping = Const(0)
+ #if self.allow_overlap:
+ # stopping = dbg.stopping_o
+ with m.If(stopping):
+ # stopping: jump back to idle
+ m.next = "ISSUE_START"
+ if flush_needed:
+ # request the icache to stop asserting "failed"
+ comb += core.icache.flush_in.eq(1)
+ # stop instruction fault
+ sync += pdecode2.instr_fault.eq(0)
+ with m.Else():
+ comb += fetch_insn_i_ready.eq(1)
+ with m.If(fetch_insn_o_valid):
+ # loop into ISSUE_START if it's a SVP64 instruction
+ # and VL == 0. this because VL==0 is a for-loop
+ # from 0 to 0 i.e. always, always a NOP.
+ cur_vl = cur_state.svstate.vl
+ with m.If(is_svp64_mode & (cur_vl == 0)):
+ # update the PC before fetching the next instruction
+ # since we are in a VL==0 loop, no instruction was
+ # executed that we could be overwriting
+ comb += self.state_w_pc.wen.eq(1 << StateRegs.PC)
+ comb += self.state_w_pc.i_data.eq(nia)
+ comb += self.insn_done.eq(1)
+ m.next = "ISSUE_START"
+ with m.Else():
+ if self.svp64_en:
+ m.next = "PRED_START" # fetching predicate
+ else:
+ m.next = "DECODE_SV" # skip predication
with m.State("PRED_START"):
- comb += pred_insn_valid_i.eq(1) # tell fetch_pred to start
- with m.If(pred_insn_ready_o): # fetch_pred acknowledged us
+ comb += pred_insn_i_valid.eq(1) # tell fetch_pred to start
+ with m.If(pred_insn_o_ready): # fetch_pred acknowledged us
m.next = "MASK_WAIT"
with m.State("MASK_WAIT"):
- comb += pred_mask_ready_i.eq(1) # ready to receive the masks
- with m.If(pred_mask_valid_o): # predication masks are ready
+ comb += pred_mask_i_ready.eq(1) # ready to receive the masks
+ with m.If(pred_mask_o_valid): # predication masks are ready
m.next = "PRED_SKIP"
# skip zeros in predicate
(skip_dststep >= cur_vl)):
# end of VL loop. Update PC and reset src/dst step
comb += self.state_w_pc.wen.eq(1 << StateRegs.PC)
- comb += self.state_w_pc.data_i.eq(nia)
+ comb += self.state_w_pc.i_data.eq(nia)
comb += new_svstate.srcstep.eq(0)
comb += new_svstate.dststep.eq(0)
- comb += update_svstate.eq(1)
+ comb += self.update_svstate.eq(1)
# synchronize with the simulator
comb += self.insn_done.eq(1)
# go back to Issue
# update new src/dst step
comb += new_svstate.srcstep.eq(skip_srcstep)
comb += new_svstate.dststep.eq(skip_dststep)
- comb += update_svstate.eq(1)
+ comb += self.update_svstate.eq(1)
# proceed to Decode
m.next = "DECODE_SV"
# pass predicate mask bits through to satellite decoders
# TODO: for SIMD this will be *multiple* bits
- sync += core.sv_pred_sm.eq(self.srcmask[0])
- sync += core.sv_pred_dm.eq(self.dstmask[0])
+ sync += core.i.sv_pred_sm.eq(self.srcmask[0])
+ sync += core.i.sv_pred_dm.eq(self.dstmask[0])
# after src/dst step have been updated, we are ready
# to decode the instruction
with m.State("DECODE_SV"):
# decode the instruction
- sync += core.e.eq(pdecode2.e)
- sync += core.state.eq(cur_state)
- sync += core.raw_insn_i.eq(dec_opcode_i)
- sync += core.bigendian_i.eq(self.core_bigendian_i)
+ with m.If(~fetch_failed):
+ sync += pdecode2.instr_fault.eq(0)
+ sync += core.i.e.eq(pdecode2.e)
+ sync += core.i.state.eq(cur_state)
+ sync += core.i.raw_insn_i.eq(dec_opcode_i)
+ sync += core.i.bigendian_i.eq(self.core_bigendian_i)
if self.svp64_en:
- sync += core.sv_rm.eq(pdecode2.sv_rm)
+ sync += core.i.sv_rm.eq(pdecode2.sv_rm)
# set RA_OR_ZERO detection in satellite decoders
- sync += core.sv_a_nz.eq(pdecode2.sv_a_nz)
+ sync += core.i.sv_a_nz.eq(pdecode2.sv_a_nz)
+ # and svp64 detection
+ sync += core.i.is_svp64_mode.eq(is_svp64_mode)
+ # and svp64 bit-rev'd ldst mode
+ ldst_dec = pdecode2.use_svp64_ldst_dec
+ sync += core.i.use_svp64_ldst_dec.eq(ldst_dec)
+ # after decoding, reset any previous exception condition,
+ # allowing it to be set again during the next execution
+ sync += pdecode2.ldst_exc.eq(0)
m.next = "INSN_EXECUTE" # move to "execute"
# handshake with execution FSM, move to "wait" once acknowledged
with m.State("INSN_EXECUTE"):
- comb += exec_insn_valid_i.eq(1) # trigger execute
- with m.If(exec_insn_ready_o): # execute acknowledged us
- m.next = "EXECUTE_WAIT"
+ # when using "single-step" mode, checking dbg.stopping_o
+ # prevents progress. allow execute to proceed once started
+ stopping = Const(0)
+ #if self.allow_overlap:
+ # stopping = dbg.stopping_o
+ with m.If(stopping):
+ # stopping: jump back to idle
+ m.next = "ISSUE_START"
+ if flush_needed:
+ # request the icache to stop asserting "failed"
+ comb += core.icache.flush_in.eq(1)
+ # stop instruction fault
+ sync += pdecode2.instr_fault.eq(0)
+ with m.Else():
+ comb += exec_insn_i_valid.eq(1) # trigger execute
+ with m.If(exec_insn_o_ready): # execute acknowledged us
+ m.next = "EXECUTE_WAIT"
with m.State("EXECUTE_WAIT"):
- # wait on "core stop" release, at instruction end
- # need to do this here, in case we are in a VL>1 loop
- with m.If(~dbg.core_stop_o & ~core_rst):
- comb += exec_pc_ready_i.eq(1)
- # see https://bugs.libre-soc.org/show_bug.cgi?id=636
- #with m.If(exec_pc_valid_o & exc_happened):
- # probably something like this:
- # sync += pdecode2.ldst_exc.eq(core.fus.get_exc("ldst0")
- # TODO: the exception info needs to be blatted
- # into pdecode.ldst_exc, and the instruction "re-run".
- # when ldst_exc.happened is set, the PowerDecoder2
- # reacts very differently: it re-writes the instruction
- # with a "trap" (calls PowerDecoder2.trap()) which
- # will *overwrite* whatever was requested and jump the
- # PC to the exception address, as well as alter MSR.
- # nothing else needs to be done other than to note
- # the change of PC and MSR (and, later, SVSTATE)
- #with m.Elif(exec_pc_valid_o):
- with m.If(exec_pc_valid_o): # replace with Elif (above)
-
- # was this the last loop iteration?
- is_last = Signal()
- cur_vl = cur_state.svstate.vl
- comb += is_last.eq(next_srcstep == cur_vl)
+ comb += exec_pc_i_ready.eq(1)
+ # see https://bugs.libre-soc.org/show_bug.cgi?id=636
+ # the exception info needs to be blatted into
+ # pdecode.ldst_exc, and the instruction "re-run".
+ # when ldst_exc.happened is set, the PowerDecoder2
+ # reacts very differently: it re-writes the instruction
+ # with a "trap" (calls PowerDecoder2.trap()) which
+ # will *overwrite* whatever was requested and jump the
+ # PC to the exception address, as well as alter MSR.
+ # nothing else needs to be done other than to note
+ # the change of PC and MSR (and, later, SVSTATE)
+ with m.If(exc_happened):
+ mmu = core.fus.get_exc("mmu0")
+ ldst = core.fus.get_exc("ldst0")
+ if mmu is not None:
+ with m.If(fetch_failed):
+ # instruction fetch: exception is from MMU
+ # reset instr_fault (highest priority)
+ sync += pdecode2.ldst_exc.eq(mmu)
+ sync += pdecode2.instr_fault.eq(0)
+ if flush_needed:
+ # request icache to stop asserting "failed"
+ comb += core.icache.flush_in.eq(1)
+ with m.If(~fetch_failed):
+ # otherwise assume it was a LDST exception
+ sync += pdecode2.ldst_exc.eq(ldst)
+
+ with m.If(exec_pc_o_valid):
+
+ # was this the last loop iteration?
+ is_last = Signal()
+ cur_vl = cur_state.svstate.vl
+ comb += is_last.eq(next_srcstep == cur_vl)
- # if either PC or SVSTATE were changed by the previous
- # instruction, go directly back to Fetch, without
- # updating either PC or SVSTATE
- with m.If(pc_changed | sv_changed):
- m.next = "ISSUE_START"
+ with m.If(pdecode2.instr_fault):
+ # reset instruction fault, try again
+ sync += pdecode2.instr_fault.eq(0)
+ m.next = "ISSUE_START"
- # also return to Fetch, when no output was a vector
- # (regardless of SRCSTEP and VL), or when the last
- # instruction was really the last one of the VL loop
- with m.Elif((~pdecode2.loop_continue) | is_last):
- # before going back to fetch, update the PC state
- # register with the NIA.
- # ok here we are not reading the branch unit.
- # TODO: this just blithely overwrites whatever
- # pipeline updated the PC
- comb += self.state_w_pc.wen.eq(1 << StateRegs.PC)
- comb += self.state_w_pc.data_i.eq(nia)
- # reset SRCSTEP before returning to Fetch
- if self.svp64_en:
- with m.If(pdecode2.loop_continue):
- comb += new_svstate.srcstep.eq(0)
- comb += new_svstate.dststep.eq(0)
- comb += update_svstate.eq(1)
- else:
+ # return directly to Decode if Execute generated an
+ # exception.
+ with m.Elif(pdecode2.ldst_exc.happened):
+ m.next = "DECODE_SV"
+
+ # if MSR, PC or SVSTATE were changed by the previous
+ # instruction, go directly back to Fetch, without
+ # updating either MSR PC or SVSTATE
+ with m.Elif(self.msr_changed | self.pc_changed |
+ self.sv_changed):
+ m.next = "ISSUE_START"
+
+ # also return to Fetch, when no output was a vector
+ # (regardless of SRCSTEP and VL), or when the last
+ # instruction was really the last one of the VL loop
+ with m.Elif((~pdecode2.loop_continue) | is_last):
+ # before going back to fetch, update the PC state
+ # register with the NIA.
+ # ok here we are not reading the branch unit.
+ # TODO: this just blithely overwrites whatever
+ # pipeline updated the PC
+ comb += self.state_w_pc.wen.eq(1 << StateRegs.PC)
+ comb += self.state_w_pc.i_data.eq(nia)
+ # reset SRCSTEP before returning to Fetch
+ if self.svp64_en:
+ with m.If(pdecode2.loop_continue):
comb += new_svstate.srcstep.eq(0)
comb += new_svstate.dststep.eq(0)
- comb += update_svstate.eq(1)
- m.next = "ISSUE_START"
+ comb += self.update_svstate.eq(1)
+ else:
+ comb += new_svstate.srcstep.eq(0)
+ comb += new_svstate.dststep.eq(0)
+ comb += self.update_svstate.eq(1)
+ m.next = "ISSUE_START"
- # returning to Execute? then, first update SRCSTEP
- with m.Else():
- comb += new_svstate.srcstep.eq(next_srcstep)
- comb += new_svstate.dststep.eq(next_dststep)
- comb += update_svstate.eq(1)
- # return to mask skip loop
- m.next = "PRED_SKIP"
+ # returning to Execute? then, first update SRCSTEP
+ with m.Else():
+ comb += new_svstate.srcstep.eq(next_srcstep)
+ comb += new_svstate.dststep.eq(next_dststep)
+ comb += self.update_svstate.eq(1)
+ # return to mask skip loop
+ m.next = "PRED_SKIP"
- with m.Else():
- comb += dbg.core_stopped_i.eq(1)
- # while stopped, allow updating the PC and SVSTATE
- with m.If(self.pc_i.ok):
- comb += self.state_w_pc.wen.eq(1 << StateRegs.PC)
- comb += self.state_w_pc.data_i.eq(self.pc_i.data)
- sync += pc_changed.eq(1)
- with m.If(self.svstate_i.ok):
- comb += new_svstate.eq(self.svstate_i.data)
- comb += update_svstate.eq(1)
- sync += sv_changed.eq(1)
# check if svstate needs updating: if so, write it to State Regfile
- with m.If(update_svstate):
- comb += self.state_w_sv.wen.eq(1<<StateRegs.SVSTATE)
- comb += self.state_w_sv.data_i.eq(new_svstate)
- sync += cur_state.svstate.eq(new_svstate) # for next clock
-
- def execute_fsm(self, m, core, pc_changed, sv_changed,
- exec_insn_valid_i, exec_insn_ready_o,
- exec_pc_valid_o, exec_pc_ready_i):
+ with m.If(self.update_svstate):
+ sync += cur_state.svstate.eq(self.new_svstate) # for next clock
+
+ def execute_fsm(self, m, core,
+ exec_insn_i_valid, exec_insn_o_ready,
+ exec_pc_o_valid, exec_pc_i_ready):
"""execute FSM
execute FSM. this interacts with the "issue" FSM
comb = m.d.comb
sync = m.d.sync
+ dbg = self.dbg
pdecode2 = self.pdecode2
+ cur_state = self.cur_state
# temporaries
- core_busy_o = core.busy_o # core is busy
- core_ivalid_i = core.ivalid_i # instruction is valid
- core_issue_i = core.issue_i # instruction is issued
- insn_type = core.e.do.insn_type # instruction MicroOp type
+ core_busy_o = core.n.o_data.busy_o # core is busy
+ core_ivalid_i = core.p.i_valid # instruction is valid
+
+ if hasattr(core, "icache"):
+ fetch_failed = core.icache.i_out.fetch_failed
+ else:
+ fetch_failed = Const(0, 1)
with m.FSM(name="exec_fsm"):
# waiting for instruction bus (stays there until not busy)
with m.State("INSN_START"):
- comb += exec_insn_ready_o.eq(1)
- with m.If(exec_insn_valid_i):
- comb += core_ivalid_i.eq(1) # instruction is valid
- comb += core_issue_i.eq(1) # and issued
- sync += sv_changed.eq(0)
- sync += pc_changed.eq(0)
- m.next = "INSN_ACTIVE" # move to "wait completion"
+ comb += exec_insn_o_ready.eq(1)
+ with m.If(exec_insn_i_valid):
+ comb += core_ivalid_i.eq(1) # instruction is valid/issued
+ sync += self.sv_changed.eq(0)
+ sync += self.pc_changed.eq(0)
+ sync += self.msr_changed.eq(0)
+ with m.If(core.p.o_ready): # only move if accepted
+ m.next = "INSN_ACTIVE" # move to "wait completion"
# instruction started: must wait till it finishes
with m.State("INSN_ACTIVE"):
- with m.If(insn_type != MicrOp.OP_NOP):
- comb += core_ivalid_i.eq(1) # instruction is valid
- # note changes to PC and SVSTATE
- with m.If(self.state_nia.wen & (1<<StateRegs.SVSTATE)):
- sync += sv_changed.eq(1)
- with m.If(self.state_nia.wen & (1<<StateRegs.PC)):
- sync += pc_changed.eq(1)
- with m.If(~core_busy_o): # instruction done!
- comb += exec_pc_valid_o.eq(1)
- with m.If(exec_pc_ready_i):
- comb += self.insn_done.eq(1)
+ # note changes to MSR, PC and SVSTATE
+ with m.If(self.state_nia.wen & (1 << StateRegs.SVSTATE)):
+ sync += self.sv_changed.eq(1)
+ with m.If(self.state_nia.wen & (1 << StateRegs.MSR)):
+ sync += self.msr_changed.eq(1)
+ with m.If(self.state_nia.wen & (1 << StateRegs.PC)):
+ sync += self.pc_changed.eq(1)
+ # and note changes to DEC/TB, to be passed to DEC/TB FSM
+ with m.If(self.state_spr.wen & (1 << StateRegs.TB)):
+ comb += self.pause_dec_tb.eq(1)
+ # but also zero-out the cur_state DEC so that, on
+ # the next instruction, if it is "enable interrupt"
+ # the delay between the DEC/TB FSM reading and updating
+ # cur_state.dec doesn't trigger a spurious interrupt.
+ # the DEC/TB FSM will read the regfile and update to
+ # the correct value, so having cur_state.dec set to zero
+ # for a while is no big deal.
+ with m.If(self.state_spr.wen & (1 << StateRegs.DEC)):
+ comb += self.pause_dec_tb.eq(1)
+ sync += cur_state.dec.eq(0) # only needs top bit clear
+ with m.If(~core_busy_o): # instruction done!
+ comb += exec_pc_o_valid.eq(1)
+ with m.If(exec_pc_i_ready):
+ # when finished, indicate "done".
+ # however, if there was an exception, the instruction
+ # is *not* yet done. this is an implementation
+ # detail: we choose to implement exceptions by
+ # taking the exception information from the LDST
+ # unit, putting that *back* into the PowerDecoder2,
+ # and *re-running the entire instruction*.
+ # if we erroneously indicate "done" here, it is as if
+ # there were *TWO* instructions:
+ # 1) the failed LDST 2) a TRAP.
+ with m.If(~pdecode2.ldst_exc.happened &
+ ~pdecode2.instr_fault):
+ comb += self.insn_done.eq(1)
m.next = "INSN_START" # back to fetch
-
- def setup_peripherals(self, m):
- comb, sync = m.d.comb, m.d.sync
-
- m.submodules.core = core = DomainRenamer("coresync")(self.core)
- m.submodules.imem = imem = self.imem
- m.submodules.dbg = dbg = self.dbg
- if self.jtag_en:
- m.submodules.jtag = jtag = self.jtag
- # TODO: UART2GDB mux, here, from external pin
- # see https://bugs.libre-soc.org/show_bug.cgi?id=499
- sync += dbg.dmi.connect_to(jtag.dmi)
-
- cur_state = self.cur_state
-
- # 4x 4k SRAM blocks. these simply "exist", they get routed in litex
- if self.sram4x4k:
- for i, sram in enumerate(self.sram4k):
- m.submodules["sram4k_%d" % i] = sram
- comb += sram.enable.eq(self.wb_sram_en)
-
- # XICS interrupt handler
- if self.xics:
- m.submodules.xics_icp = icp = self.xics_icp
- m.submodules.xics_ics = ics = self.xics_ics
- comb += icp.ics_i.eq(ics.icp_o) # connect ICS to ICP
- sync += cur_state.eint.eq(icp.core_irq_o) # connect ICP to core
-
- # GPIO test peripheral
- if self.gpio:
- m.submodules.simple_gpio = simple_gpio = self.simple_gpio
-
- # connect one GPIO output to ICS bit 15 (like in microwatt soc.vhdl)
- # XXX causes litex ECP5 test to get wrong idea about input and output
- # (but works with verilator sim *sigh*)
- #if self.gpio and self.xics:
- # comb += self.int_level_i[15].eq(simple_gpio.gpio_o[0])
-
- # instruction decoder
- pdecode = create_pdecode()
- m.submodules.dec2 = pdecode2 = self.pdecode2
- if self.svp64_en:
- m.submodules.svp64 = svp64 = self.svp64
-
- # convenience
- dmi, d_reg, d_cr, d_xer, = dbg.dmi, dbg.d_gpr, dbg.d_cr, dbg.d_xer
- intrf = self.core.regs.rf['int']
-
- # clock delay power-on reset
- cd_por = ClockDomain(reset_less=True)
- cd_sync = ClockDomain()
- core_sync = ClockDomain("coresync")
- m.domains += cd_por, cd_sync, core_sync
-
- ti_rst = Signal(reset_less=True)
- delay = Signal(range(4), reset=3)
- with m.If(delay != 0):
- m.d.por += delay.eq(delay - 1)
- comb += cd_por.clk.eq(ClockSignal())
-
- # power-on reset delay
- core_rst = ResetSignal("coresync")
- comb += ti_rst.eq(delay != 0 | dbg.core_rst_o | ResetSignal())
- comb += core_rst.eq(ti_rst)
-
- # busy/halted signals from core
- comb += self.busy_o.eq(core.busy_o)
- comb += pdecode2.dec.bigendian.eq(self.core_bigendian_i)
-
- # temporary hack: says "go" immediately for both address gen and ST
- l0 = core.l0
- ldst = core.fus.fus['ldst0']
- st_go_edge = rising_edge(m, ldst.st.rel_o)
- m.d.comb += ldst.ad.go_i.eq(ldst.ad.rel_o) # link addr-go direct to rel
- m.d.comb += ldst.st.go_i.eq(st_go_edge) # link store-go to rising rel
-
- return core_rst
+ # terminate returns directly to INSN_START
+ with m.If(dbg.terminate_i):
+ # comb += self.insn_done.eq(1) - no because it's not
+ m.next = "INSN_START" # back to fetch
def elaborate(self, platform):
- m = Module()
+ m = super().elaborate(platform)
# convenience
comb, sync = m.d.comb, m.d.sync
cur_state = self.cur_state
core = self.core
# set up peripherals and core
- core_rst = self.setup_peripherals(m)
+ core_rst = self.core_rst
- # reset current state if core reset requested
- with m.If(core_rst):
- m.d.sync += self.cur_state.eq(0)
-
- # PC and instruction from I-Memory
- comb += self.pc_o.eq(cur_state.pc)
- pc_changed = Signal() # note write to PC
- sv_changed = Signal() # note write to SVSTATE
-
- # read state either from incoming override or from regfile
- # TODO: really should be doing MSR in the same way
- pc = state_get(m, core_rst, self.pc_i,
- "pc", # read PC
- self.state_r_pc, StateRegs.PC)
- svstate = state_get(m, core_rst, self.svstate_i,
- "svstate", # read SVSTATE
- self.state_r_sv, StateRegs.SVSTATE)
-
- # don't write pc every cycle
- comb += self.state_w_pc.wen.eq(0)
- comb += self.state_w_pc.data_i.eq(0)
-
- # don't read msr every cycle
- comb += self.state_r_msr.ren.eq(0)
+ # indicate to outside world if any FU is still executing
+ comb += self.any_busy.eq(core.n.o_data.any_busy_o) # any FU executing
# address of the next instruction, in the absence of a branch
# depends on the instruction size
nia = Signal(64)
# connect up debug signals
- # TODO comb += core.icache_rst_i.eq(dbg.icache_rst_o)
- comb += dbg.terminate_i.eq(core.core_terminate_o)
- comb += dbg.state.pc.eq(pc)
- comb += dbg.state.svstate.eq(svstate)
- comb += dbg.state.msr.eq(cur_state.msr)
+ with m.If(core.o.core_terminate_o):
+ comb += dbg.terminate_i.eq(1)
# pass the prefix mode from Fetch to Issue, so the latter can loop
# on VL==0
# these are the handshake signals between each
# fetch FSM can run as soon as the PC is valid
- fetch_pc_valid_i = Signal() # Execute tells Fetch "start next read"
- fetch_pc_ready_o = Signal() # Fetch Tells SVSTATE "proceed"
+ fetch_pc_i_valid = Signal() # Execute tells Fetch "start next read"
+ fetch_pc_o_ready = Signal() # Fetch Tells SVSTATE "proceed"
# fetch FSM hands over the instruction to be decoded / issued
- fetch_insn_valid_o = Signal()
- fetch_insn_ready_i = Signal()
+ fetch_insn_o_valid = Signal()
+ fetch_insn_i_ready = Signal()
# predicate fetch FSM decodes and fetches the predicate
- pred_insn_valid_i = Signal()
- pred_insn_ready_o = Signal()
+ pred_insn_i_valid = Signal()
+ pred_insn_o_ready = Signal()
# predicate fetch FSM delivers the masks
- pred_mask_valid_o = Signal()
- pred_mask_ready_i = Signal()
+ pred_mask_o_valid = Signal()
+ pred_mask_i_ready = Signal()
# issue FSM delivers the instruction to the be executed
- exec_insn_valid_i = Signal()
- exec_insn_ready_o = Signal()
+ exec_insn_i_valid = Signal()
+ exec_insn_o_ready = Signal()
# execute FSM, hands over the PC/SVSTATE back to the issue FSM
- exec_pc_valid_o = Signal()
- exec_pc_ready_i = Signal()
+ exec_pc_o_valid = Signal()
+ exec_pc_i_ready = Signal()
# the FSMs here are perhaps unusual in that they detect conditions
# then "hold" information, combinatorially, for the core
# Issue is where the VL for-loop # lives. the ready/valid
# signalling is used to communicate between the four.
- self.fetch_fsm(m, core, pc, svstate, nia, is_svp64_mode,
- fetch_pc_ready_o, fetch_pc_valid_i,
- fetch_insn_valid_o, fetch_insn_ready_i)
+ self.fetch_fsm(m, dbg, core, core_rst, nia, is_svp64_mode,
+ fetch_pc_o_ready, fetch_pc_i_valid,
+ fetch_insn_o_valid, fetch_insn_i_ready)
- self.issue_fsm(m, core, pc_changed, sv_changed, nia,
+ self.issue_fsm(m, core, nia,
dbg, core_rst, is_svp64_mode,
- fetch_pc_ready_o, fetch_pc_valid_i,
- fetch_insn_valid_o, fetch_insn_ready_i,
- pred_insn_valid_i, pred_insn_ready_o,
- pred_mask_valid_o, pred_mask_ready_i,
- exec_insn_valid_i, exec_insn_ready_o,
- exec_pc_valid_o, exec_pc_ready_i)
+ fetch_pc_o_ready, fetch_pc_i_valid,
+ fetch_insn_o_valid, fetch_insn_i_ready,
+ pred_insn_i_valid, pred_insn_o_ready,
+ pred_mask_o_valid, pred_mask_i_ready,
+ exec_insn_i_valid, exec_insn_o_ready,
+ exec_pc_o_valid, exec_pc_i_ready)
if self.svp64_en:
self.fetch_predicate_fsm(m,
- pred_insn_valid_i, pred_insn_ready_o,
- pred_mask_valid_o, pred_mask_ready_i)
+ pred_insn_i_valid, pred_insn_o_ready,
+ pred_mask_o_valid, pred_mask_i_ready)
- self.execute_fsm(m, core, pc_changed, sv_changed,
- exec_insn_valid_i, exec_insn_ready_o,
- exec_pc_valid_o, exec_pc_ready_i)
+ self.execute_fsm(m, core,
+ exec_insn_i_valid, exec_insn_o_ready,
+ exec_pc_o_valid, exec_pc_i_ready)
- # whatever was done above, over-ride it if core reset is held
+ # whatever was done above, over-ride it if core reset is held.
+ # set NIA to pc_at_reset
with m.If(core_rst):
- sync += nia.eq(0)
-
- # this bit doesn't have to be in the FSM: connect up to read
- # regfiles on demand from DMI
- self.do_dmi(m, dbg)
-
- # DEC and TB inc/dec FSM. copy of DEC is put into CoreState,
- # (which uses that in PowerDecoder2 to raise 0x900 exception)
- self.tb_dec_fsm(m, cur_state.dec)
+ sync += nia.eq(self.core.pc_at_reset)
return m
- def do_dmi(self, m, dbg):
- """deals with DMI debug requests
-
- currently only provides read requests for the INT regfile, CR and XER
- it will later also deal with *writing* to these regfiles.
- """
- comb = m.d.comb
- sync = m.d.sync
- dmi, d_reg, d_cr, d_xer, = dbg.dmi, dbg.d_gpr, dbg.d_cr, dbg.d_xer
- intrf = self.core.regs.rf['int']
-
- with m.If(d_reg.req): # request for regfile access being made
- # TODO: error-check this
- # XXX should this be combinatorial? sync better?
- if intrf.unary:
- comb += self.int_r.ren.eq(1<<d_reg.addr)
- else:
- comb += self.int_r.addr.eq(d_reg.addr)
- comb += self.int_r.ren.eq(1)
- d_reg_delay = Signal()
- sync += d_reg_delay.eq(d_reg.req)
- with m.If(d_reg_delay):
- # data arrives one clock later
- comb += d_reg.data.eq(self.int_r.data_o)
- comb += d_reg.ack.eq(1)
-
- # sigh same thing for CR debug
- with m.If(d_cr.req): # request for regfile access being made
- comb += self.cr_r.ren.eq(0b11111111) # enable all
- d_cr_delay = Signal()
- sync += d_cr_delay.eq(d_cr.req)
- with m.If(d_cr_delay):
- # data arrives one clock later
- comb += d_cr.data.eq(self.cr_r.data_o)
- comb += d_cr.ack.eq(1)
-
- # aaand XER...
- with m.If(d_xer.req): # request for regfile access being made
- comb += self.xer_r.ren.eq(0b111111) # enable all
- d_xer_delay = Signal()
- sync += d_xer_delay.eq(d_xer.req)
- with m.If(d_xer_delay):
- # data arrives one clock later
- comb += d_xer.data.eq(self.xer_r.data_o)
- comb += d_xer.ack.eq(1)
-
- def tb_dec_fsm(self, m, spr_dec):
- """tb_dec_fsm
-
- this is a FSM for updating either dec or tb. it runs alternately
- DEC, TB, DEC, TB. note that SPR pipeline could have written a new
- value to DEC, however the regfile has "passthrough" on it so this
- *should* be ok.
-
- see v3.0B p1097-1099 for Timeer Resource and p1065 and p1076
- """
-
- comb, sync = m.d.comb, m.d.sync
- fast_rf = self.core.regs.rf['fast']
- fast_r_dectb = fast_rf.r_ports['issue'] # DEC/TB
- fast_w_dectb = fast_rf.w_ports['issue'] # DEC/TB
-
- with m.FSM() as fsm:
-
- # initiates read of current DEC
- with m.State("DEC_READ"):
- comb += fast_r_dectb.addr.eq(FastRegs.DEC)
- comb += fast_r_dectb.ren.eq(1)
- m.next = "DEC_WRITE"
-
- # waits for DEC read to arrive (1 cycle), updates with new value
- with m.State("DEC_WRITE"):
- new_dec = Signal(64)
- # TODO: MSR.LPCR 32-bit decrement mode
- comb += new_dec.eq(fast_r_dectb.data_o - 1)
- comb += fast_w_dectb.addr.eq(FastRegs.DEC)
- comb += fast_w_dectb.wen.eq(1)
- comb += fast_w_dectb.data_i.eq(new_dec)
- sync += spr_dec.eq(new_dec) # copy into cur_state for decoder
- m.next = "TB_READ"
-
- # initiates read of current TB
- with m.State("TB_READ"):
- comb += fast_r_dectb.addr.eq(FastRegs.TB)
- comb += fast_r_dectb.ren.eq(1)
- m.next = "TB_WRITE"
-
- # waits for read TB to arrive, initiates write of current TB
- with m.State("TB_WRITE"):
- new_tb = Signal(64)
- comb += new_tb.eq(fast_r_dectb.data_o + 1)
- comb += fast_w_dectb.addr.eq(FastRegs.TB)
- comb += fast_w_dectb.wen.eq(1)
- comb += fast_w_dectb.data_i.eq(new_tb)
- m.next = "DEC_READ"
-
- return m
-
- def __iter__(self):
- yield from self.pc_i.ports()
- yield self.pc_o
- yield self.memerr_o
- yield from self.core.ports()
- yield from self.imem.ports()
- yield self.core_bigendian_i
- yield self.busy_o
-
- def ports(self):
- return list(self)
-
- def external_ports(self):
- ports = self.pc_i.ports()
- ports += [self.pc_o, self.memerr_o, self.core_bigendian_i, self.busy_o,
- ]
-
- if self.jtag_en:
- ports += list(self.jtag.external_ports())
- else:
- # don't add DMI if JTAG is enabled
- ports += list(self.dbg.dmi.ports())
-
- ports += list(self.imem.ibus.fields.values())
- ports += list(self.core.l0.cmpi.wb_bus().fields.values())
-
- if self.sram4x4k:
- for sram in self.sram4k:
- ports += list(sram.bus.fields.values())
-
- if self.xics:
- ports += list(self.xics_icp.bus.fields.values())
- ports += list(self.xics_ics.bus.fields.values())
- ports.append(self.int_level_i)
-
- if self.gpio:
- ports += list(self.simple_gpio.bus.fields.values())
- ports.append(self.gpio_o)
-
- return ports
-
- def ports(self):
- return list(self)
-
class TestIssuer(Elaboratable):
def __init__(self, pspec):
self.ti = TestIssuerInternal(pspec)
-
self.pll = DummyPLL(instance=True)
+ self.dbg_rst_i = Signal(reset_less=True)
+
# PLL direct clock or not
self.pll_en = hasattr(pspec, "use_pll") and pspec.use_pll
if self.pll_en:
self.pll_test_o = Signal(reset_less=True)
self.pll_vco_o = Signal(reset_less=True)
- self.clk_sel_i = Signal(reset_less=True)
+ self.clk_sel_i = Signal(2, reset_less=True)
+ self.ref_clk = ClockSignal() # can't rename it but that's ok
+ self.pllclk_clk = ClockSignal("pllclk")
def elaborate(self, platform):
m = Module()
comb = m.d.comb
- # TestIssuer runs at direct clock
+ # TestIssuer nominally runs at main clock, actually it is
+ # all combinatorial internally except for coresync'd components
m.submodules.ti = ti = self.ti
- cd_int = ClockDomain("coresync")
if self.pll_en:
# ClockSelect runs at PLL output internal clock rate
# PLL clock established. has the side-effect of running clklsel
# at the PLL's speed (see DomainRenamer("pllclk") above)
- pllclk = ClockSignal("pllclk")
+ pllclk = self.pllclk_clk
comb += pllclk.eq(pll.clk_pll_o)
# wire up external 24mhz to PLL
- comb += pll.clk_24_i.eq(ClockSignal())
-
+ #comb += pll.clk_24_i.eq(self.ref_clk)
# output 18 mhz PLL test signal, and analog oscillator out
comb += self.pll_test_o.eq(pll.pll_test_o)
comb += self.pll_vco_o.eq(pll.pll_vco_o)
# internal clock is set to selector clock-out. has the side-effect of
# running TestIssuer at this speed (see DomainRenamer("intclk") above)
- intclk = ClockSignal("coresync")
+ # debug clock runs at coresync internal clock
+ if self.ti.dbg_domain != 'sync':
+ cd_dbgsync = ClockDomain("dbgsync")
+ intclk = ClockSignal(self.ti.core_domain)
+ dbgclk = ClockSignal(self.ti.dbg_domain)
+ # XXX BYPASS PLL XXX
+ # XXX BYPASS PLL XXX
+ # XXX BYPASS PLL XXX
if self.pll_en:
- comb += intclk.eq(pll.clk_pll_o)
+ comb += intclk.eq(self.ref_clk)
+ assert self.ti.core_domain != 'sync', \
+ "cannot set core_domain to sync and use pll at the same time"
else:
- comb += intclk.eq(ClockSignal())
+ if self.ti.core_domain != 'sync':
+ comb += intclk.eq(ClockSignal())
+ if self.ti.dbg_domain != 'sync':
+ dbgclk = ClockSignal(self.ti.dbg_domain)
+ comb += dbgclk.eq(intclk)
+ comb += self.ti.dbg_rst_i.eq(self.dbg_rst_i)
return m
def ports(self):
return list(self.ti.ports()) + list(self.pll.ports()) + \
- [ClockSignal(), ResetSignal()]
+ [ClockSignal(), ResetSignal()]
def external_ports(self):
ports = self.ti.external_ports()
ports.append(ResetSignal())
if self.pll_en:
ports.append(self.clk_sel_i)
+ ports.append(self.pll.clk_24_i)
ports.append(self.pll_test_o)
ports.append(self.pll_vco_o)
+ ports.append(self.pllclk_clk)
+ ports.append(self.ref_clk)
return ports
'div': 1,
'mul': 1,
'shiftrot': 1
- }
+ }
pspec = TestMemPspec(ldst_ifacetype='bare_wb',
imem_ifacetype='bare_wb',
- addr_wid=48,
+ addr_wid=64,
mask_wid=8,
reg_wid=64,
units=units)
projects / soc.git / blobdiff