59 lines
1.5 KiB
Python
59 lines
1.5 KiB
Python
from migen.fhdl.structure import *
|
|
from migen.bus import wishbone
|
|
from migen.flow.actor import *
|
|
|
|
class Reader(Actor):
|
|
def __init__(self):
|
|
self.bus = wishbone.Interface()
|
|
super().__init__(
|
|
("address", Sink, [("a", BV(30))]),
|
|
("data", Source, [("d", BV(32))]))
|
|
|
|
def get_fragment(self):
|
|
bus_stb = Signal()
|
|
|
|
data_reg_loaded = Signal()
|
|
data_reg = Signal(BV(32))
|
|
|
|
comb = [
|
|
self.busy.eq(data_reg_loaded),
|
|
self.bus.we.eq(0),
|
|
bus_stb.eq(self.endpoints["address"].stb & (~data_reg_loaded | self.endpoints["data"].ack)),
|
|
self.bus.cyc.eq(bus_stb),
|
|
self.bus.stb.eq(bus_stb),
|
|
self.bus.adr.eq(self.token("address").a),
|
|
self.endpoints["address"].ack.eq(self.bus.ack),
|
|
self.endpoints["data"].stb.eq(data_reg_loaded),
|
|
self.token("data").d.eq(data_reg)
|
|
]
|
|
sync = [
|
|
If(self.endpoints["data"].ack,
|
|
data_reg_loaded.eq(0)
|
|
),
|
|
If(self.bus.ack,
|
|
data_reg_loaded.eq(1),
|
|
data_reg.eq(self.bus.dat_r)
|
|
)
|
|
]
|
|
|
|
return Fragment(comb, sync)
|
|
|
|
class Writer(Actor):
|
|
def __init__(self):
|
|
self.bus = wishbone.Interface()
|
|
super().__init__(
|
|
("address_data", Sink, [("a", BV(30)), ("d", BV(32))]))
|
|
|
|
def get_fragment(self):
|
|
comb = [
|
|
self.busy.eq(0),
|
|
self.bus.we.eq(1),
|
|
self.bus.cyc.eq(self.endpoints["address_data"].stb),
|
|
self.bus.stb.eq(self.endpoints["address_data"].stb),
|
|
self.bus.adr.eq(self.token("address_data").a),
|
|
self.bus.sel.eq(0xf),
|
|
self.bus.dat_w.eq(self.token("address_data").d),
|
|
self.endpoints["address_data"].ack.eq(self.bus.ack)
|
|
]
|
|
return Fragment(comb)
|