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frotend/avalon: Another simplifiation pass on start condition.

This commit is contained in:
Florent Kermarrec 2023-05-31 10:03:39 +02:00
parent 10837c6a53
commit 9befeb0761
1 changed files with 43 additions and 61 deletions
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62
litedram/frontend/avalon.py
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@ -28,7 +28,7 @@ class LiteDRAMAvalonMM2Native(LiteXModule):
downconvert = ratio > 1
upconvert = ratio < 1
# DownConverter (Optional).
# Data-Width Converter (Optional).
if avalon_data_width != port_data_width:
if avalon_data_width > port_data_width:
addr_shift = -log2_int(avalon_data_width//port_data_width)
@ -39,24 +39,24 @@ class LiteDRAMAvalonMM2Native(LiteXModule):
address_width = port.address_width + addr_shift,
data_width = avalon_data_width
)
self.submodules += LiteDRAMNativePortConverter(new_port, port)
self.converter = LiteDRAMNativePortConverter(new_port, port)
port = new_port
# # #
# Internal Signals.
offset = (base_address >> log2_int(port.data_width//8))
burst_count = Signal(9)
burst_start = Signal()
burst_active = Signal()
address = Signal(port.address_width)
address_offset = Signal(port.address_width)
byteenable = Signal(avalon_data_width//8)
writedata = Signal(avalon_data_width)
start = Signal()
cmd_ready_seen = Signal()
cmd_ready_count = Signal(9)
self.comb += address_offset.eq(base_address >> log2_int(port.data_width//8))
# Layouts.
cmd_layout = [("address", len(address))]
wdata_layout = [
@ -64,58 +64,39 @@ class LiteDRAMAvalonMM2Native(LiteXModule):
("byteenable", avalon_data_width//8),
]
self.comb += [
burst_start .eq(avalon.burstcount > 1),
burst_active.eq(burst_count > 0),
]
self.sync += [
If(start,
byteenable.eq(avalon.byteenable),
writedata.eq(avalon.writedata),
burst_count.eq(avalon.burstcount),
address.eq(avalon.address - offset),
address.eq(avalon.address - address_offset),
)
]
# FSM.
self.submodules.fsm = fsm = FSM(reset_state="START")
self.fsm = fsm = FSM(reset_state="START")
fsm.act("START",
avalon.waitrequest.eq(1),
If(~burst_start,
port.cmd.addr.eq(avalon.address - offset),
If(avalon.burstcount <= 1,
port.cmd.addr.eq(avalon.address - address_offset),
port.cmd.we.eq(avalon.write),
port.cmd.valid.eq(avalon.read | avalon.write)
),
If(avalon.read | avalon.write,
If(downconvert,
start.eq(1)
).Else(
start.eq(burst_start | port.cmd.ready)
)
),
If(start,
If(downconvert,
avalon.waitrequest.eq(1)
).Else(
If(~burst_start,
If((avalon.burstcount > 1) | (downconvert == True) | port.cmd.ready,
start.eq(1),
If((downconvert == False) & (avalon.burstcount <= 1),
avalon.waitrequest.eq(0)
)
),
If(avalon.write,
If(burst_start,
If(avalon.burstcount > 1,
NextState("BURST_WRITE")
).Else(
If(downconvert,
port.wdata.data.eq(avalon.writedata),
port.wdata.valid.eq(1),
port.wdata.we.eq(avalon.byteenable),
),
NextValue(writedata, avalon.writedata),
port.cmd.last.eq(1),
NextState("SINGLE_WRITE")
)
).Elif(avalon.read,
If(burst_start,
If(avalon.burstcount > 1,
avalon.waitrequest.eq(0),
NextValue(cmd_ready_count, avalon.burstcount),
NextState("BURST_READ")
@ -126,12 +107,13 @@ class LiteDRAMAvalonMM2Native(LiteXModule):
)
)
)
)
fsm.act("SINGLE_WRITE",
avalon.waitrequest.eq(1),
port.rdata.ready.eq(0),
If(downconvert,
If((downconvert == True),
port.cmd.addr.eq(address),
port.cmd.we.eq(1),
port.cmd.valid.eq(1),
@ -150,13 +132,13 @@ class LiteDRAMAvalonMM2Native(LiteXModule):
port.wdata.we.eq(byteenable),
If(port.wdata.ready,
If(downconvert,
If((downconvert == True),
avalon.waitrequest.eq(0)
),
NextValue(writedata, avalon.writedata),
port.flush.eq(1),
If(downconvert,
If((downconvert == True),
NextValue(cmd_ready_seen, 0)
).Else(
NextValue(port.cmd.last, 1)
@ -170,7 +152,7 @@ class LiteDRAMAvalonMM2Native(LiteXModule):
avalon.waitrequest.eq(1),
port.rdata.ready.eq(1),
If(downconvert,
If((downconvert == True),
port.cmd.addr.eq(address),
port.cmd.we.eq(0),
port.cmd.valid.eq(1),
@ -188,7 +170,7 @@ class LiteDRAMAvalonMM2Native(LiteXModule):
avalon.readdata.eq(port.rdata.data),
avalon.readdatavalid.eq(1),
If(downconvert,
If((downconvert == True),
port.cmd.valid.eq(0),
avalon.waitrequest.eq(0),
NextValue(cmd_ready_seen, 0),
@ -211,7 +193,7 @@ class LiteDRAMAvalonMM2Native(LiteXModule):
wdata_fifo.sink.payload.byteenable.eq(avalon.byteenable),
wdata_fifo.sink.valid.eq(avalon.write & ~avalon.waitrequest),
If(avalon.write & burst_active,
If(avalon.write & (burst_count > 0),
If(cmd_fifo.sink.ready & cmd_fifo.sink.valid,
NextValue(burst_count, burst_count - 1),
NextValue(address, address + burst_increment)