litex/miscope/miio.py

44 lines
1.1 KiB
Python

from migen.fhdl.structure import *
from migen.bus import csr
from migen.bank import description, csrgen
from migen.bank.description import *
class MiIo:
#
# Definition
#
def __init__(self, address, width, mode="IO", interface=None):
self.address = address
self.width = width
self.mode = mode.upper()
self.interface = interface
self.words = int((2**bits_for(width-1))/8)
if "I" in self.mode:
self.i = Signal(self.width)
self.ireg = description.RegisterField("i", self.width, READ_ONLY, WRITE_ONLY)
if "O" in self.mode:
self.o = Signal(self.width)
self.oreg = description.RegisterField("o", self.width)
self.bank = csrgen.Bank([self.oreg, self.ireg], address=self.address)
def get_fragment(self):
comb = []
if "I" in self.mode:
comb += [self.ireg.field.w.eq(self.i)]
if "O" in self.mode:
comb += [self.o.eq(self.oreg.field.r)]
return Fragment(comb) + self.bank.get_fragment()
#
# Driver
#
def set(self, data):
self.interface.write(self.bank.get_base(), data)
def get(self):
return self.interface.read(self.bank.get_base() + self.words)