litex/examples/dataflow_dma.py

97 lines
2.5 KiB
Python

from random import Random
from migen.fhdl import verilog
from migen.flow.ala import *
from migen.flow.network import *
from migen.actorlib import dma_wishbone
from migen.actorlib.sim import *
from migen.bus import wishbone
from migen.sim.generic import Simulator
from migen.sim.icarus import Runner
class MyPeripheral:
def __init__(self):
self.bus = wishbone.Interface()
self.ack_en = Signal()
self.prng = Random(763627)
def do_simulation(self, s):
# Only authorize acks on certain cycles to simulate variable latency.
s.wr(self.ack_en, self.prng.randrange(0, 2))
def get_fragment(self):
comb = [
self.bus.ack.eq(self.bus.cyc & self.bus.stb & self.ack_en),
self.bus.dat_r.eq(self.bus.adr + 4)
]
return Fragment(comb, sim=[self.do_simulation])
def adrgen_gen():
for i in range(10):
print("Address: " + str(i))
yield Token("address", {"a": i})
def dumper_gen():
while True:
t = Token("data")
yield t
print("Received: " + str(t.value["d"]))
def test_reader():
print("*** Testing reader")
adrgen = SimActor(adrgen_gen(), ("address", Source, [("a", BV(30))]))
reader = dma_wishbone.Reader()
dumper = SimActor(dumper_gen(), ("data", Sink, [("d", BV(32))]))
g = DataFlowGraph()
g.add_connection(adrgen, reader)
g.add_connection(reader, dumper)
comp = CompositeActor(g)
peripheral = MyPeripheral()
interconnect = wishbone.InterconnectPointToPoint(reader.bus, peripheral.bus)
def end_simulation(s):
s.interrupt = adrgen.done and not s.rd(comp.busy)
fragment = comp.get_fragment() \
+ peripheral.get_fragment() \
+ interconnect.get_fragment() \
+ Fragment(sim=[end_simulation])
sim = Simulator(fragment, Runner())
sim.run()
def trgen_gen():
for i in range(10):
a = i
d = i+10
print("Address: " + str(a) + " Data: " + str(d))
yield Token("address_data", {"a": a, "d": d})
def test_writer():
print("*** Testing writer")
trgen = SimActor(trgen_gen(), ("address_data", Source, [("a", BV(30)), ("d", BV(32))]))
writer = dma_wishbone.Writer()
g = DataFlowGraph()
g.add_connection(trgen, writer)
comp = CompositeActor(g)
peripheral = MyPeripheral()
tap = wishbone.Tap(peripheral.bus)
interconnect = wishbone.InterconnectPointToPoint(writer.bus, peripheral.bus)
def end_simulation(s):
s.interrupt = trgen.done and not s.rd(comp.busy)
fragment = comp.get_fragment() \
+ peripheral.get_fragment() \
+ tap.get_fragment() \
+ interconnect.get_fragment() \
+ Fragment(sim=[end_simulation])
sim = Simulator(fragment, Runner())
sim.run()
test_reader()
test_writer()