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corelogic: convert timeline to function and move to misc

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This commit is contained in:
Sebastien Bourdeauducq 2012-03-15 20:25:44 +01:00
parent 1665f293a6
commit e969b9afc3
3 changed files with 34 additions and 38 deletions
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13
migen/bus/wishbone2csr.py
View file

@ -1,16 +1,12 @@
from migen.bus import wishbone
from migen.bus import csr
from migen.fhdl.structure import *
from migen.corelogic import timeline
from migen.corelogic.misc import timeline
class WB2CSR:
def __init__(self):
self.wishbone = wishbone.Interface()
self.csr = csr.Interface()
self.timeline = timeline.Timeline(self.wishbone.cyc & self.wishbone.stb,
[(1, [self.csr.we.eq(self.wishbone.we)]),
(2, [self.wishbone.ack.eq(1)]),
(3, [self.wishbone.ack.eq(0)])])
def get_fragment(self):
sync = [
@ -19,4 +15,9 @@ class WB2CSR:
self.csr.adr.eq(self.wishbone.adr[:14]),
self.wishbone.dat_r.eq(self.csr.dat_r)
]
return Fragment(sync=sync) + self.timeline.get_fragment()
sync += timeline(self.wishbone.cyc & self.wishbone.stb, [
(1, [self.csr.we.eq(self.wishbone.we)]),
(2, [self.wishbone.ack.eq(1)]),
(3, [self.wishbone.ack.eq(0)])
])
return Fragment(sync=sync)

27
migen/corelogic/misc.py
View file

@ -64,3 +64,30 @@ def chooser(signal, shift, output, n=None, reverse=False):
cases.append([Constant(i, shift.bv), output.eq(signal[s*w:(s+1)*w])])
cases[n-1][0] = Default()
return Case(shift, *cases)
def timeline(trigger, events):
lastevent = max([e[0] for e in events])
counter = Signal(BV(bits_for(lastevent)))
counterlogic = If(counter != Constant(0, counter.bv),
counter.eq(counter + Constant(1, counter.bv))
).Elif(trigger,
counter.eq(Constant(1, counter.bv))
)
# insert counter reset if it doesn't naturally overflow
# (test if lastevent+1 is a power of 2)
if (lastevent & (lastevent + 1)) != 0:
counterlogic = If(counter == lastevent,
counter.eq(Constant(0, counter.bv))
).Else(
counterlogic
)
def get_cond(e):
if e[0] == 0:
return trigger & (counter == Constant(0, counter.bv))
else:
return counter == Constant(e[0], counter.bv)
sync = [If(get_cond(e), *e[1]) for e in events]
sync.append(counterlogic)
return sync

32
migen/corelogic/timeline.py
View file

@ -1,32 +0,0 @@
from migen.fhdl.structure import *
class Timeline:
def __init__(self, trigger, events):
self.trigger = trigger
self.events = events
self.lastevent = max([e[0] for e in events])
def get_fragment(self):
counter = Signal(BV(bits_for(self.lastevent)))
counterlogic = If(counter != Constant(0, counter.bv),
counter.eq(counter + Constant(1, counter.bv))
).Elif(self.trigger,
counter.eq(Constant(1, counter.bv))
)
# insert counter reset if it doesn't automatically overflow
# (test if self.lastevent+1 is a power of 2)
if (self.lastevent & (self.lastevent + 1)) != 0:
counterlogic = If(counter == self.lastevent,
counter.eq(Constant(0, counter.bv))
).Else(
counterlogic
)
def get_cond(e):
if e[0] == 0:
return self.trigger & (counter == Constant(0, counter.bv))
else:
return counter == Constant(e[0], counter.bv)
sync = [If(get_cond(e), *e[1]) for e in self.events]
sync.append(counterlogic)
return Fragment(sync=sync)