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bus/lasmibus: add separate req/data ack to target and initiator

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This commit is contained in:
Sebastien Bourdeauducq 2013-07-10 19:09:51 +02:00
parent af6ef0a3b4
commit 43fe16ef73
1 changed files with 35 additions and 17 deletions
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52
migen/bus/lasmibus.py
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@ -174,12 +174,14 @@ class Initiator(Module):
s.wr(self.bus.dat_w, 0)
s.wr(self.bus.dat_we, 0)
if not self.done:
if self.transaction is not None and s.rd(self.bus.ack):
s.wr(self.bus.stb, 0)
if isinstance(self.transaction, TRead):
self.transaction_end = s.cycle_counter + self.bus.read_latency
else:
self.transaction_end = s.cycle_counter + self.bus.write_latency - 1
if self.transaction is not None:
if s.rd(self.bus.req_ack):
s.wr(self.bus.stb, 0)
if s.rd(self.bus.dat_ack):
if isinstance(self.transaction, TRead):
self.transaction_end = s.cycle_counter + self.bus.read_latency
else:
self.transaction_end = s.cycle_counter + self.bus.write_latency - 1
if self.transaction is None or s.cycle_counter == self.transaction_end:
if self.transaction is not None:
@ -224,38 +226,54 @@ class TargetModel:
self.last_bank += 1
return self.last_bank
class _ReqFIFO(Module):
def __init__(self, req_queue_size, bank):
self.req_queue_size = req_queue_size
self.bank = bank
self.contents = []
def do_simulation(self, s):
if len(self.contents) < self.req_queue_size:
if s.rd(self.bank.stb):
self.contents.append((s.rd(self.bank.we), s.rd(self.bank.adr)))
s.wr(self.bank.req_ack, 1)
else:
s.wr(self.bank.req_ack, 0)
s.wr(self.bank.lock, bool(self.contents))
class Target(Module):
def __init__(self, model, *ifargs, **ifkwargs):
self.model = model
self.bus = Interface(*ifargs, **ifkwargs)
self.req_fifos = [_ReqFIFO(self.bus.req_queue_size, getattr(self.bus, "bank"+str(nb)))
for nb in range(self.bus.nbanks)]
self.submodules += self.req_fifos
self.rd_pipeline = [None]*self.bus.read_latency
self.wr_pipeline = [None]*(self.bus.write_latency + 1)
def do_simulation(self, s):
# determine banks with pending requests
pending_banks = set()
for nb in range(self.bus.nbanks):
bank = getattr(self.bus, "bank"+str(nb))
if s.rd(bank.stb) and not s.rd(bank.ack):
pending_banks.add(nb)
pending_banks = set(nb for nb, rf in enumerate(self.req_fifos) if rf.contents)
# issue new transactions
selected_bank_n = self.model.select_bank(pending_banks)
selected_transaction = None
for nb in range(self.bus.nbanks):
bank = getattr(self.bus, "bank"+str(nb))
if nb == selected_bank_n:
s.wr(bank.ack, 1)
s.wr(bank.dat_ack, 1)
selected_transaction = self.req_fifos[nb].contents.pop(0)
else:
s.wr(bank.ack, 0)
s.wr(bank.dat_ack, 0)
rd_transaction = None
wr_transaction = None
if selected_bank_n >= 0:
selected_bank = getattr(self.bus, "bank"+str(selected_bank_n))
if s.rd(selected_bank.we):
wr_transaction = selected_bank_n, s.rd(selected_bank.adr)
we, adr = selected_transaction
if we:
wr_transaction = selected_bank_n, adr
else:
rd_transaction = selected_bank_n, s.rd(selected_bank.adr)
rd_transaction = selected_bank_n, adr
# data pipeline
self.rd_pipeline.append(rd_transaction)