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drtio: CrossDomainRequest

This commit is contained in:
Sebastien Bourdeauducq 2016-10-20 23:37:59 +08:00
parent 9790c5d9ed
commit 6a88229e6a
2 changed files with 82 additions and 0 deletions

View File

@ -2,6 +2,8 @@ from types import SimpleNamespace
from migen import *
from migen.genlib.fsm import *
from migen.genlib.fifo import AsyncFIFO
from migen.genlib.cdc import PulseSynchronizer, NoRetiming
def layout_len(l):
@ -311,3 +313,34 @@ class RTPacketSatellite(Module):
tx_dp.stb.eq(1),
If(tx_dp.done, NextState("IDLE"))
)
class _CrossDomainRequest(Module):
def __init__(self, domain,
req_stb, req_ack, req_data,
srv_stb, srv_ack, srv_data):
dsync = getattr(self.sync, domain)
request = PulseSynchronizer("sys", domain)
reply = PulseSynchronizer(domain, "sys")
self.submodules += request, reply
ongoing = Signal()
self.comb += request.i.eq(~ongoing & req_stb)
self.sync += [
req_ack.eq(reply.o),
If(req_stb, ongoing.eq(1)),
If(req_ack, ongoing.eq(0))
]
if req_data is not None:
srv_data_r = Signal.like(srv_data)
dsync += If(srv_stb & srv_ack, srv_data_r.eq(srv_data))
self.specials += NoRetiming(srv_data_r)
self.sync += If(reply.o, req_data.eq(srv_data_r))
dsync += [
If(request.o, srv_stb.eq(1)),
If(srv_ack, srv_stb.eq(0))
]
self.comb += reply.i.eq(srv_stb & srv_ack)

View File

@ -1,9 +1,11 @@
import unittest
from types import SimpleNamespace
import random
from migen import *
from artiq.gateware.drtio.rt_packets import *
from artiq.gateware.drtio.rt_packets import _CrossDomainRequest
class PacketInterface:
@ -119,3 +121,50 @@ class TestSatellite(unittest.TestCase):
yield
run_simulation(dut, [send(), receive()])
self.assertEqual(tx_times, rx_times)
class TestCrossDomainRequest(unittest.TestCase):
def test_cross_domain_request(self):
for sys_freq in 3, 6, 11:
for srv_freq in 3, 6, 11:
prng = random.Random(1)
req_stb = Signal()
req_ack = Signal()
req_data = Signal(8)
srv_stb = Signal()
srv_ack = Signal()
srv_data = Signal(8)
test_seq = [93, 92, 19, 39, 91, 30, 12, 91, 38, 42]
received_seq = []
def requester():
for i in range(len(test_seq)):
yield req_stb.eq(1)
yield
while not (yield req_ack):
yield
received_seq.append((yield req_data))
yield req_stb.eq(0)
for j in range(prng.randrange(0, 10)):
yield
def server():
for data in test_seq:
while not (yield srv_stb):
yield
for j in range(prng.randrange(0, 10)):
yield
yield srv_data.eq(data)
yield srv_ack.eq(1)
yield
yield srv_ack.eq(0)
yield
dut = _CrossDomainRequest("srv",
req_stb, req_ack, req_data,
srv_stb, srv_ack, srv_data)
run_simulation(dut,
{"sys": requester(), "srv": server()},
{"sys": sys_freq, "srv": srv_freq})
self.assertEqual(test_seq, received_seq)