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):
+ 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
# waiting (zzz)
with m.State("IDLE"):
- comb += fetch_pc_ready_o.eq(1)
- with m.If(fetch_pc_valid_i):
+ comb += fetch_pc_o_ready.eq(1)
+ with m.If(fetch_pc_i_valid):
# 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)
+ comb += self.imem.a_i_valid.eq(1)
+ comb += self.imem.f_i_valid.eq(1)
sync += cur_state.pc.eq(pc)
sync += cur_state.svstate.eq(svstate) # and svstate
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)
+ 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)
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)
+ 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
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)
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
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):
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,
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
# 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
+ comb += fetch_pc_i_valid.eq(1) # tell fetch to start
+ 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
# 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):
+ 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.
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
# 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
+ 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)
+ comb += exec_pc_i_ready.eq(1)
# see https://bugs.libre-soc.org/show_bug.cgi?id=636
- #with m.If(exec_pc_valid_o & exc_happened):
+ #with m.If(exec_pc_o_valid & exc_happened):
# probably something like this:
# sync += pdecode2.ldst_exc.eq(core.fus.get_exc("ldst0")
# TODO: the exception info needs to be blatted
# 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)
+ #with m.Elif(exec_pc_o_valid):
+ with m.If(exec_pc_o_valid): # replace with Elif (above)
# was this the last loop iteration?
is_last = Signal()
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):
+ 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
# temporaries
core_busy_o = core.busy_o # core is busy
- core_ivalid_i = core.ivalid_i # instruction is valid
+ core_ii_valid = core.ii_valid # instruction is valid
core_issue_i = core.issue_i # instruction is issued
insn_type = core.e.do.insn_type # instruction MicroOp type
# 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 += exec_insn_o_ready.eq(1)
+ with m.If(exec_insn_i_valid):
+ comb += core_ii_valid.eq(1) # instruction is valid
comb += core_issue_i.eq(1) # and issued
sync += sv_changed.eq(0)
sync += pc_changed.eq(0)
# 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
+ comb += core_ii_valid.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 += exec_pc_o_valid.eq(1)
+ with m.If(exec_pc_i_ready):
comb += self.insn_done.eq(1)
m.next = "INSN_START" # back to fetch
# 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
# 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)
+ 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,
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)
+ 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):
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