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core/mac/sram: simplify last_be code

This commit is contained in:
Florent Kermarrec 2018-09-07 16:26:49 +02:00
parent ce72e34f56
commit 5106bcdc0c
1 changed files with 26 additions and 18 deletions
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44
liteeth/core/mac/sram.py
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@ -28,17 +28,21 @@ class LiteEthMACSRAMWriter(Module, AutoCSR):
# length computation
inc = Signal(3)
inc_cases = {}
inc_cases["default"] = inc.eq(4)
if endianness == "big":
inc_cases[0b1000] = inc.eq(1)
inc_cases[0b0100] = inc.eq(2)
inc_cases[0b0010] = inc.eq(3)
self.comb += Case(sink.last_be, {
0b1000 : inc.eq(1),
0b0100 : inc.eq(2),
0b0010 : inc.eq(3),
"default" : inc.eq(4)
})
else:
inc_cases[0b0001] = inc.eq(1)
inc_cases[0b0010] = inc.eq(2)
inc_cases[0b0100] = inc.eq(3)
self.comb += Case(sink.last_be, inc_cases)
self.comb += Case(sink.last_be, {
0b0001 : inc.eq(1),
0b0010 : inc.eq(2),
0b0100 : inc.eq(3),
"default" : inc.eq(4)
})
counter = Signal(lengthbits)
counter_reset = Signal()
@ -206,18 +210,22 @@ class LiteEthMACSRAMReader(Module, AutoCSR):
)
length_lsb = fifo.source.length[0:2]
length_cases = {}
if endianness == "big":
length_cases[0] = source.last_be.eq(0b0001)
length_cases[1] = source.last_be.eq(0b1000)
length_cases[2] = source.last_be.eq(0b0100)
length_cases[3] = source.last_be.eq(0b0010)
self.comb += If(last,
Case(length_lsb, {
0 : source.last.be.eq(0b0001),
1 : source.last.be.eq(0b1000),
2 : source.last.be.eq(0b0100),
3 : source.last_be.eq(0b0010)
}))
else:
length_cases[0] = source.last_be.eq(0b1000)
length_cases[1] = source.last_be.eq(0b0001)
length_cases[2] = source.last_be.eq(0b0010)
length_cases[3] = source.last_be.eq(0b0100)
self.comb += If(last, Case(length_lsb, length_cases))
self.comb += If(last,
Case(length_lsb, {
0 : source.last.be.eq(0b1000),
1 : source.last.be.eq(0b0001),
2 : source.last.be.eq(0b0010),
3 : source.last_be.eq(0b0100)
}))
fsm.act("SEND",
source.valid.eq(1),