comb on intpick
authorLuke Kenneth Casson Leighton <lkcl@lkcl.net>
Mon, 13 May 2019 22:24:07 +0000 (23:24 +0100)
committerLuke Kenneth Casson Leighton <lkcl@lkcl.net>
Mon, 13 May 2019 22:24:07 +0000 (23:24 +0100)
src/experiment/compalu.py
src/experiment/score6600.py

index 69dbff597c5c1c970c47ee3d824126e6d553608a..d9e0108dfb8f82ba7cd2e9c08ba5155387ce5762 100644 (file)
@@ -33,7 +33,7 @@ class ComputationUnitNoDelay(Elaboratable):
         # is in effect a "3-way revolving door".  At no time may all 3
         # latches be set at the same time.
 
-        # opcode latch (not using go_rd_i)
+        # opcode latch (not using go_rd_i) - inverted so that busy resets to 0
         m.d.comb += opc_l.s.eq(self.issue_i) # XXX NOTE: INVERTED FROM book!
         m.d.comb += opc_l.r.eq(self.go_wr_i) # XXX NOTE: INVERTED FROM book!
 
index 0d334ec1d34b1cfacee40b4dbfd9fd6aeb9cc0bd..5415ae9ec212c3f080dad8968ad3d849946b4d7d 100644 (file)
@@ -256,8 +256,8 @@ class Scoreboard(Elaboratable):
         m.d.comb += intpick1.req_rel_i[0:2].eq(cu.req_rel_o[0:2])
         int_readable_o = intfus.readable_o
         int_writable_o = intfus.writable_o
-        m.d.sync += intpick1.readable_i[0:2].eq(int_readable_o[0:2])
-        m.d.sync += intpick1.writable_i[0:2].eq(int_writable_o[0:2])
+        m.d.comb += intpick1.readable_i[0:2].eq(int_readable_o[0:2])
+        m.d.comb += intpick1.writable_i[0:2].eq(int_writable_o[0:2])
 
         #---------
         # Connect Register File(s)