33 lines
967 B
Python
33 lines
967 B
Python
from functools import partial
|
|
|
|
from migen.fhdl.structure import *
|
|
from migen.bus import wishbone
|
|
from migen.corelogic import timeline
|
|
|
|
class Inst:
|
|
def __init__(self, adr_width, rd_timing):
|
|
self.bus = wishbone.Slave("norflash")
|
|
d = partial(declare_signal, self)
|
|
d("adr", BV(adr_width-1))
|
|
d("d", BV(16))
|
|
d("oe_n")
|
|
d("we_n")
|
|
d("ce_n")
|
|
d("rst_n")
|
|
self.timeline = timeline.Inst(self.bus.cyc_i & self.bus.stb_i,
|
|
[(0, [self.adr.eq(Cat(0, self.bus.adr_i[2:adr_width]))]),
|
|
(rd_timing, [
|
|
self.bus.dat_o[16:].eq(self.d),
|
|
self.adr.eq(Cat(1, self.bus.adr_i[2:adr_width]))]),
|
|
(2*rd_timing, [
|
|
self.bus.dat_o[:16].eq(self.d),
|
|
self.bus.ack_o.eq(1)]),
|
|
(2*rd_timing+1, [
|
|
self.bus.ack_o.eq(0)])])
|
|
|
|
def get_fragment(self):
|
|
comb = [self.oe_n.eq(0), self.we_n.eq(1),
|
|
self.ce_n.eq(0), self.rst_n.eq(1)]
|
|
return Fragment(comb, pads={self.adr, self.d, self.oe_n, self.we_n, self.ce_n, self.rst_n}) \
|
|
+ self.timeline.get_fragment()
|