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
+ #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
# soc-cocotb-sim, and err.. all needs sorting out, argh
# main instruction core. suitable for prototyping / demo only
self.core = core = NonProductionCore(pspec)
- self.core_rst = ResetSignal("coresync")
+ self.core_rst = ResetSignal(self.core_domain)
# instruction decoder. goes into Trap Record
#pdecode = create_pdecode()
# DMI interface
self.dbg = CoreDebug()
+ self.dbg_rst_i = Signal(reset_less=True)
# instruction go/monitor
self.pc_o = Signal(64, reset_less=True)
# 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("coresync")
+ csd = DomainRenamer(self.core_domain)
dbd = DomainRenamer(self.dbg_domain)
m.submodules.core = core = csd(self.core)
# 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
+ 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
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)
+ 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)
- # debug clock is same as coresync, but reset is *main external*
+ # connect external reset signal to DMI Reset
if self.dbg_domain != "sync":
dbg_rst = ResetSignal(self.dbg_domain)
- comb += dbg_rst.eq(ResetSignal())
+ 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
with m.If(core_rst):
m.d.sync += self.cur_state.eq(0)
+ # 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
# 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.DR])
+ comb += self.imem.i_in.virt_mode.eq(msr[MSR.IR]) # Instr. Redir (VM)
with m.FSM(name='fetch_fsm'):
# waiting (zzz)
with m.State("IDLE"):
- with m.If(~dbg.stopping_o & ~fetch_failed):
+ # 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 & ~fetch_failed):
+ 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
# dummy pause to find out why simulation is not keeping up
with m.State("INSN_READ"):
- if self.allow_overlap:
- stopping = dbg.stopping_o
- else:
- stopping = Const(0)
+ # 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():
- with m.If(self.imem.f_busy_o & ~fetch_failed): # zzz...
+ 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
- insn = get_insn(self.imem.f_instr_o, cur_state.pc)
+ 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 += 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_o.eq(insn)
m.next = "INSN_READY"
# TODO: probably can start looking at pdecode2.rm_dec
# wait for an instruction to arrive from Fetch
with m.State("INSN_WAIT"):
- if self.allow_overlap:
- stopping = dbg.stopping_o
- else:
- stopping = Const(0)
+ # 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"
# handshake with execution FSM, move to "wait" once acknowledged
with m.State("INSN_EXECUTE"):
- comb += exec_insn_i_valid.eq(1) # trigger execute
- with m.If(exec_insn_o_ready): # 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
cur_vl = cur_state.svstate.vl
comb += is_last.eq(next_srcstep == cur_vl)
+ with m.If(pdecode2.instr_fault):
+ # reset instruction fault, try again
+ sync += pdecode2.instr_fault.eq(0)
+ m.next = "ISSUE_START"
+
# return directly to Decode if Execute generated an
# exception.
- with m.If(pdecode2.ldst_exc.happened):
+ with m.Elif(pdecode2.ldst_exc.happened):
m.next = "DECODE_SV"
# if MSR, PC or SVSTATE were changed by the previous
comb += core.icache.flush_in.eq(1)
# stop instruction fault
sync += pdecode2.instr_fault.eq(0)
+ # if terminated return to idle
+ with m.If(dbg.terminate_i):
+ m.next = "ISSUE_START"
# check if svstate needs updating: if so, write it to State Regfile
with m.If(self.update_svstate):
comb = m.d.comb
sync = m.d.sync
+ dbg = self.dbg
pdecode2 = self.pdecode2
# temporaries
# there were *TWO* instructions:
# 1) the failed LDST 2) a TRAP.
with m.If(~pdecode2.ldst_exc.happened &
- ~fetch_failed):
+ ~pdecode2.instr_fault):
comb += self.insn_done.eq(1)
m.next = "INSN_START" # back to fetch
+ # 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 = super().elaborate(platform)
nia = Signal(64)
# connect up debug signals
- comb += dbg.terminate_i.eq(core.o.core_terminate_o)
+ 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
#self.ti = TestIssuerInternalInOrder(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:
# internal clock is set to selector clock-out. has the side-effect of
# running TestIssuer at this speed (see DomainRenamer("intclk") above)
# debug clock runs at coresync internal clock
- cd_coresync = ClockDomain("coresync")
- #m.domains += cd_coresync
if self.ti.dbg_domain != 'sync':
cd_dbgsync = ClockDomain("dbgsync")
- #m.domains += cd_dbgsync
- intclk = ClockSignal("coresync")
+ 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(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
projects / soc.git / blobdiff