artiq/soc/artiqlib/rtio/phy.py

31 lines
1001 B
Python

from migen.fhdl.std import *
from migen.genlib.cdc import MultiReg
from artiqlib.rtio.rbus import create_rbus
class SimplePHY(Module):
def __init__(self, pads, output_only_pads=set()):
self.rbus = create_rbus(0, pads, output_only_pads)
self.loopback_latency = 3
# # #
for pad, chif in zip(pads, self.rbus):
o_pad = Signal()
self.sync.rio += If(chif.o_stb, o_pad.eq(chif.o_value))
if hasattr(chif, "oe"):
ts = TSTriple()
i_pad = Signal()
self.sync.rio += ts.oe.eq(chif.oe)
self.comb += ts.o.eq(o_pad)
self.specials += MultiReg(ts.i, i_pad, "rio"), \
ts.get_tristate(pad)
i_pad_d = Signal()
self.sync.rio += i_pad_d.eq(i_pad)
self.comb += chif.i_stb.eq(i_pad ^ i_pad_d), \
chif.i_value.eq(i_pad)
else:
self.comb += pad.eq(o_pad)