From: Luke Kenneth Casson Leighton <lkcl@lkcl.net>
Date: Sat, 25 Jul 2020 14:33:38 +0000 (+0100)
Subject: wait until pipeline indicates that its output is valid in compunit test
X-Git-Tag: semi_working_ecp5~549
X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=0d6210336e58f8e11e632374a53f0001338280c6;p=soc.git

wait until pipeline indicates that its output is valid in compunit test
DIV and other long pipelines only set wrmask when a result is available
the previous test, "is wrmask zero if so exit" was therefore reading
invalid data.

it was a matter of coincidence that all other compunit tests were only
one stage long that the wrmask *happened* to be valid
---

diff --git a/src/soc/fu/compunits/test/test_compunit.py b/src/soc/fu/compunits/test/test_compunit.py
index 09c1beee..9ac469f4 100644
--- a/src/soc/fu/compunits/test/test_compunit.py
+++ b/src/soc/fu/compunits/test/test_compunit.py
@@ -80,6 +80,13 @@ def set_operand(cu, dec2, sim):
 
 def get_cu_outputs(cu, code):
     res = {}
+    # wait for pipeline to indicate valid.  this because for long
+    # pipelines (or FSMs) the write mask is only valid at that time.
+    while True:
+        valid_o = yield cu.alu.n.valid_o
+        if valid_o:
+            break
+        yield
     wrmask = yield cu.wrmask
     wr_rel_o = yield cu.wr.rel
     print("get_cu_outputs", cu.n_dst, wrmask, wr_rel_o)