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lasmi: simplify usage for the user (it's the job of the controller to manage write/read latencies on acks)

This commit is contained in:
Florent Kermarrec 2015-03-01 21:22:12 +01:00
parent f58394f6af
commit 6d83a112e6
3 changed files with 43 additions and 25 deletions
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30
misoclib/mem/sdram/bus/lasmibus.py
View File

@ -18,7 +18,8 @@ class Interface(Record):
("we", 1, DIR_M_TO_S),
("stb", 1, DIR_M_TO_S),
("req_ack", 1, DIR_S_TO_M),
("dat_ack", 1, DIR_S_TO_M),
("dat_w_ack", 1, DIR_S_TO_M),
("dat_r_ack", 1, DIR_S_TO_M),
("lock", 1, DIR_S_TO_M)
]
if nbanks > 1:
@ -77,7 +78,9 @@ class Crossbar(Module):
else:
controller_selected = [1]*nmasters
master_req_acks = [0]*nmasters
master_dat_acks = [0]*nmasters
master_dat_w_acks = [0]*nmasters
master_dat_r_acks = [0]*nmasters
rrs = [roundrobin.RoundRobin(nmasters, roundrobin.SP_CE) for n in range(self._nbanks)]
self.submodules += rrs
for nb, rr in enumerate(rrs):
@ -109,11 +112,28 @@ class Crossbar(Module):
]
master_req_acks = [master_req_ack | ((rr.grant == nm) & bank_selected[nm] & bank.req_ack)
for nm, master_req_ack in enumerate(master_req_acks)]
master_dat_acks = [master_dat_ack | ((rr.grant == nm) & bank.dat_ack)
for nm, master_dat_ack in enumerate(master_dat_acks)]
master_dat_w_acks = [master_dat_w_ack | ((rr.grant == nm) & bank.dat_w_ack)
for nm, master_dat_w_ack in enumerate(master_dat_w_acks)]
master_dat_r_acks = [master_dat_r_ack | ((rr.grant == nm) & bank.dat_r_ack)
for nm, master_dat_r_ack in enumerate(master_dat_r_acks)]
for nm, master_dat_w_ack in enumerate(master_dat_w_acks):
for i in range(self._write_latency):
new_master_dat_w_ack = Signal()
self.sync += new_master_dat_w_ack.eq(master_dat_w_ack)
master_dat_w_ack = new_master_dat_w_ack
master_dat_w_acks[nm] = master_dat_w_ack
for nm, master_dat_r_ack in enumerate(master_dat_r_acks):
for i in range(self._read_latency):
new_master_dat_r_ack = Signal()
self.sync += new_master_dat_r_ack.eq(master_dat_r_ack)
master_dat_r_ack = new_master_dat_r_ack
master_dat_r_acks[nm] = master_dat_r_ack
self.comb += [master.req_ack.eq(master_req_ack) for master, master_req_ack in zip(self._masters, master_req_acks)]
self.comb += [master.dat_ack.eq(master_dat_ack) for master, master_dat_ack in zip(self._masters, master_dat_acks)]
self.comb += [master.dat_w_ack.eq(master_dat_w_ack) for master, master_dat_w_ack in zip(self._masters, master_dat_w_acks)]
self.comb += [master.dat_r_ack.eq(master_dat_r_ack) for master, master_dat_r_ack in zip(self._masters, master_dat_r_acks)]
# route data writes
controller_selected_wl = controller_selected

11
misoclib/mem/sdram/bus/wishbone2lasmi.py
View File

@ -105,8 +105,6 @@ class WB2LASMI(Module, AutoCSR):
fsm = FSM(reset_state="IDLE")
self.submodules += fsm
fsm.delayed_enter("EVICT_DATAD", "EVICT_DATA", lasmim.write_latency-1)
fsm.delayed_enter("REFILL_DATAD", "REFILL_DATA", lasmim.read_latency-1)
fsm.act("IDLE",
If(self.wishbone.cyc & self.wishbone.stb, NextState("TEST_HIT"))
@ -135,7 +133,7 @@ class WB2LASMI(Module, AutoCSR):
If(lasmim.req_ack, NextState("EVICT_WAIT_DATA_ACK"))
)
fsm.act("EVICT_WAIT_DATA_ACK",
If(lasmim.dat_ack, NextState("EVICT_DATAD"))
If(lasmim.dat_w_ack, NextState("EVICT_DATA"))
)
fsm.act("EVICT_DATA",
write_to_lasmi.eq(1),
@ -155,12 +153,10 @@ class WB2LASMI(Module, AutoCSR):
)
fsm.act("REFILL_REQUEST",
lasmim.stb.eq(1),
If(lasmim.req_ack, NextState("REFILL_WAIT_DATA_ACK"))
)
fsm.act("REFILL_WAIT_DATA_ACK",
If(lasmim.dat_ack, NextState("REFILL_DATAD"))
If(lasmim.req_ack, NextState("REFILL_DATA"))
)
fsm.act("REFILL_DATA",
If(lasmim.dat_r_ack,
write_from_lasmi.eq(1),
word_inc.eq(1),
If(word_is_last(word),
@ -169,3 +165,4 @@ class WB2LASMI(Module, AutoCSR):
NextState("REFILL_REQUEST")
)
)
)

5
misoclib/mem/sdram/lasmicon/bankmachine.py
View File

@ -41,7 +41,7 @@ class BankMachine(Module):
self.req_fifo.we.eq(req.stb),
req.req_ack.eq(self.req_fifo.writable),
self.req_fifo.re.eq(req.dat_ack),
self.req_fifo.re.eq(req.dat_w_ack | req.dat_r_ack),
req.lock.eq(self.req_fifo.readable)
]
reqf = self.req_fifo.dout
@ -100,7 +100,8 @@ class BankMachine(Module):
If(hit,
# NB: write-to-read specification is enforced by multiplexer
self.cmd.stb.eq(1),
req.dat_ack.eq(self.cmd.ack),
req.dat_w_ack.eq(self.cmd.ack & reqf.we),
req.dat_r_ack.eq(self.cmd.ack & ~reqf.we),
self.cmd.is_read.eq(~reqf.we),
self.cmd.is_write.eq(reqf.we),
self.cmd.cas_n.eq(0),