35 lines
844 B
Python
35 lines
844 B
Python
from migen.fhdl.structure import *
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from migen.fhdl.module import Module
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from migen.bank.description import *
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from migen.bank.eventmanager import *
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class Timer(Module, AutoCSR):
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def __init__(self, width=32):
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self._load = CSRStorage(width)
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self._reload = CSRStorage(width)
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self._en = CSRStorage()
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self._update_value = CSR()
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self._value = CSRStatus(width)
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self.submodules.ev = EventManager()
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self.ev.zero = EventSourceProcess()
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self.ev.finalize()
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###
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value = Signal(width)
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self.sync += [
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If(self._en.storage,
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If(value == 0,
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# set reload to 0 to disable reloading
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value.eq(self._reload.storage)
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).Else(
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value.eq(value - 1)
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)
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).Else(
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value.eq(self._load.storage)
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),
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If(self._update_value.re, self._value.status.eq(value))
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]
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self.comb += self.ev.zero.trigger.eq(value != 0)
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