From a0e0a8cd07bffc75eb2f73b692c6d6b699423937 Mon Sep 17 00:00:00 2001 From: Jaro Habiger Date: Tue, 3 Nov 2020 10:10:07 +0100 Subject: [PATCH] lib.fifo: fix level on fifo full --- nmigen/lib/fifo.py | 4 ++-- tests/test_lib_fifo.py | 33 ++++++++++++++++++++++++++++++++- 2 files changed, 34 insertions(+), 3 deletions(-) diff --git a/nmigen/lib/fifo.py b/nmigen/lib/fifo.py index d0b79bd..bbe0e9d 100644 --- a/nmigen/lib/fifo.py +++ b/nmigen/lib/fifo.py @@ -380,8 +380,8 @@ class AsyncFIFO(Elaboratable, FIFOInterface): r_empty.eq(consume_r_gry == produce_r_gry), ] - m.d[self._w_domain] += self.w_level.eq((produce_w_bin - consume_w_bin)[:self._ctr_bits-1]) - m.d.comb += self.r_level.eq((produce_r_bin - consume_r_bin)[:self._ctr_bits-1]) + m.d[self._w_domain] += self.w_level.eq((produce_w_bin - consume_w_bin)) + m.d.comb += self.r_level.eq((produce_r_bin - consume_r_bin)) storage = Memory(width=self.width, depth=self.depth) w_port = m.submodules.w_port = storage.write_port(domain=self._w_domain) diff --git a/tests/test_lib_fifo.py b/tests/test_lib_fifo.py index 7de265f..c8674ba 100644 --- a/tests/test_lib_fifo.py +++ b/tests/test_lib_fifo.py @@ -302,4 +302,35 @@ class AsyncFIFOSimCase(FHDLTestCase): simulator = Simulator(fifo) simulator.add_clock(100e-6) simulator.add_sync_process(testbench) - simulator.run() \ No newline at end of file + simulator.run() + + def check_async_fifo_level(self, fifo, fill_in, expected_level): + write_done = Signal() + + def write_process(): + for i in range(fill_in): + yield fifo.w_data.eq(i) + yield fifo.w_en.eq(1) + yield + yield fifo.w_en.eq(0) + yield + yield + self.assertEqual((yield fifo.w_level), expected_level) + yield write_done.eq(1) + + def read_process(): + while not (yield write_done): + yield + self.assertEqual((yield fifo.r_level), expected_level) + + simulator = Simulator(fifo) + simulator.add_clock(100e-6, domain="write") + simulator.add_sync_process(write_process, domain="write") + simulator.add_clock(50e-6, domain="read") + simulator.add_sync_process(read_process, domain="read") + with simulator.write_vcd("test.vcd"): + simulator.run() + + def test_async_fifo_level_full(self): + fifo = AsyncFIFO(width=32, depth=8, r_domain="read", w_domain="write") + self.check_async_fifo_level(fifo, fill_in=10, expected_level=8) -- 2.30.2