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ttl_simple: support differential io

This commit is contained in:
Robert Jördens 2018-03-05 19:12:49 +00:00 committed by Robert Jordens
parent 956098c213
commit e356150ac4
1 changed files with 18 additions and 7 deletions
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25
artiq/gateware/rtio/phy/ttl_simple.py
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@ -1,13 +1,15 @@
from migen import * from migen import *
from migen.genlib.cdc import MultiReg from migen.genlib.cdc import MultiReg
from migen.genlib.io import DifferentialInput, DifferentialOutput
from artiq.gateware.rtio import rtlink from artiq.gateware.rtio import rtlink
class Output(Module): class Output(Module):
def __init__(self, pad): def __init__(self, pad, pad_n=None):
self.rtlink = rtlink.Interface(rtlink.OInterface(1)) self.rtlink = rtlink.Interface(rtlink.OInterface(1))
self.probes = [pad] pad_o = Signal(reset_less=True)
self.probes = [pad_o]
override_en = Signal() override_en = Signal()
override_o = Signal() override_o = Signal()
self.overrides = [override_en, override_o] self.overrides = [override_en, override_o]
@ -20,15 +22,19 @@ class Output(Module):
pad_k.eq(self.rtlink.o.data) pad_k.eq(self.rtlink.o.data)
), ),
If(override_en, If(override_en,
pad.eq(override_o) pad_o.eq(override_o)
).Else( ).Else(
pad.eq(pad_k) pad_o.eq(pad_k)
) )
] ]
if pad_n is None:
self.comb += pad.eq(pad_o)
else:
self.specials += DifferentialOutput(pad_o, pad, pad_n)
class Input(Module): class Input(Module):
def __init__(self, pad): def __init__(self, pad, pad_n=None):
self.rtlink = rtlink.Interface( self.rtlink = rtlink.Interface(
rtlink.OInterface(2, 2), rtlink.OInterface(2, 2),
rtlink.IInterface(1)) rtlink.IInterface(1))
@ -49,8 +55,13 @@ class Input(Module):
] ]
i = Signal() i = Signal()
i_d = Signal() i_d = Signal(reset_less=True)
self.specials += MultiReg(pad, i, "rio_phy") pad_i = Signal()
if pad_n is None:
self.comb += pad_i.eq(pad)
else:
self.specials += DifferentialInput(pad, pad_n, pad_i)
self.specials += MultiReg(pad_i, i, "rio_phy")
self.sync.rio_phy += i_d.eq(i) self.sync.rio_phy += i_d.eq(i)
self.comb += [ self.comb += [
self.rtlink.i.stb.eq( self.rtlink.i.stb.eq(