return list(self)
+class TestIssuerInternal(TestIssuerBase):
+ """TestIssuer - reads instructions from TestMemory and issues them
-# Fetch Finite State Machine.
-# WARNING: there are currently DriverConflicts but it's actually working.
-# TODO, here: everything that is global in nature, information from the
-# main TestIssuerInternal, needs to move to either ispec() or ospec().
-# not only that: TestIssuerInternal.imem can entirely move into here
-# because imem is only ever accessed inside the FetchFSM.
-class FetchFSM(ControlBase):
- def __init__(self, allow_overlap, svp64_en, imem, core_rst,
- pdecode2, cur_state,
- dbg, core, svstate, nia, is_svp64_mode):
- self.allow_overlap = allow_overlap
- self.svp64_en = svp64_en
- self.imem = imem
- self.core_rst = core_rst
- self.pdecode2 = pdecode2
- self.cur_state = cur_state
- self.dbg = dbg
- self.core = core
- self.svstate = svstate
- self.nia = nia
- self.is_svp64_mode = is_svp64_mode
-
- # set up pipeline ControlBase and allocate i/o specs
- # (unusual: normally done by the Pipeline API)
- super().__init__(stage=self)
- self.p.i_data, self.n.o_data = self.new_specs(None)
- self.i, self.o = self.p.i_data, self.n.o_data
-
- # next 3 functions are Stage API Compliance
- def setup(self, m, i):
- pass
-
- def ispec(self):
- return FetchInput()
-
- def ospec(self):
- return FetchOutput()
+ 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 elaborate(self, platform):
+ def fetch_fsm(self, m, dbg, core, pc, msr, svstate, 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
it 32-bit at a time to detect SVP64 prefixes, and will optionally
read a 2nd 32-bit quantity if that occurs.
"""
- m = super().elaborate(platform)
-
- dbg = self.dbg
- core = self.core
- pc = self.i.pc
- msr = self.i.msr
- svstate = self.svstate
- nia = self.nia
- is_svp64_mode = self.is_svp64_mode
- fetch_pc_o_ready = self.p.o_ready
- fetch_pc_i_valid = self.p.i_valid
- fetch_insn_o_valid = self.n.o_valid
- fetch_insn_i_ready = self.n.i_ready
-
comb = m.d.comb
sync = m.d.sync
pdecode2 = self.pdecode2
cur_state = self.cur_state
- dec_opcode_o = pdecode2.dec.raw_opcode_in # raw opcode
+ dec_opcode_i = pdecode2.dec.raw_opcode_in # raw opcode
# also note instruction fetch failed
if hasattr(core, "icache"):
with m.If(~svp64.is_svp64_mode):
# with no prefix, store the instruction
# and hand it directly to the next FSM
- sync += dec_opcode_o.eq(insn)
+ sync += dec_opcode_i.eq(insn)
m.next = "INSN_READY"
with m.Else():
# fetch the rest of the instruction from memory
else:
# not SVP64 - 32-bit only
sync += nia.eq(cur_state.pc + 4)
- sync += dec_opcode_o.eq(insn)
+ sync += dec_opcode_i.eq(insn)
m.next = "INSN_READY"
with m.State("INSN_READ2"):
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)
+ sync += dec_opcode_i.eq(insn)
m.next = "INSN_READY"
# TODO: probably can start looking at pdecode2.rm_dec
# here or maybe even in INSN_READ state, if svp64_mode
with m.If(fetch_insn_i_ready):
m.next = "IDLE"
- # whatever was done above, over-ride it if core reset is held
- with m.If(self.core_rst):
- sync += nia.eq(0)
-
- return m
-
-
-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_predicate_fsm(self, m,
pred_insn_i_valid, pred_insn_o_ready,
# Issue is where the VL for-loop # lives. the ready/valid
# signalling is used to communicate between the four.
- # set up Fetch FSM
- fetch = FetchFSM(self.allow_overlap, self.svp64_en,
- self.imem, core_rst, pdecode2, cur_state,
- dbg, core,
- dbg.state.svstate, # combinatorially same
- nia, is_svp64_mode)
- m.submodules.fetch = fetch
- # connect up in/out data to existing Signals
- comb += fetch.p.i_data.pc.eq(dbg.state.pc) # combinatorially same
- comb += fetch.p.i_data.msr.eq(dbg.state.msr) # combinatorially same
- # and the ready/valid signalling
- comb += fetch_pc_o_ready.eq(fetch.p.o_ready)
- comb += fetch.p.i_valid.eq(fetch_pc_i_valid)
- comb += fetch_insn_o_valid.eq(fetch.n.o_valid)
- comb += fetch.n.i_ready.eq(fetch_insn_i_ready)
+ self.fetch_fsm(m, dbg, core, dbg.state.pc, dbg.state.msr,
+ dbg.state.svstate, 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, nia,
dbg, core_rst, is_svp64_mode,
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
+ with m.If(core_rst):
+ sync += nia.eq(0)
+
return m
projects / soc.git / commitdiff