From: Luke Kenneth Casson Leighton <lkcl@lkcl.net>
Date: Sun, 2 Jun 2019 12:43:11 +0000 (+0100)
Subject: whoops forgot to make CU decisions based on latched opcode
X-Git-Tag: div_pipeline~1907
X-Git-Url: https://git.libre-soc.org/?p=soc.git;a=commitdiff_plain;h=f3ed08b862733ccac2068438d320eba202bc4204

whoops forgot to make CU decisions based on latched opcode
---

diff --git a/src/experiment/compalu.py b/src/experiment/compalu.py
index 41b73d11..1735e24c 100644
--- a/src/experiment/compalu.py
+++ b/src/experiment/compalu.py
@@ -51,6 +51,7 @@ class ComputationUnitNoDelay(Elaboratable):
         self.go_die_i = Signal() # go die (reset)
 
         self.oper_i = Signal(opwid, reset_less=True) # opcode in
+        self.imm_i = Signal(rwid, reset_less=True) # immediate in
         self.src1_i = Signal(rwid, reset_less=True) # oper1 in
         self.src2_i = Signal(rwid, reset_less=True) # oper2 in
 
@@ -102,11 +103,11 @@ class ComputationUnitNoDelay(Elaboratable):
         with m.If(opc_l.qn):
             m.d.sync += self.counter.eq(0)
         with m.If(req_l.qn & busy_o & (self.counter == 0)):
-            with m.If(self.oper_i == 2): # MUL, to take 5 instructions
+            with m.If(self.alu.op == 2): # MUL, to take 5 instructions
                 m.d.sync += self.counter.eq(5)
-            with m.Elif(self.oper_i == 3): # SHIFT to take 7
+            with m.Elif(self.alu.op == 3): # SHIFT to take 7
                 m.d.sync += self.counter.eq(7)
-            with m.Elif(self.oper_i >= 4): # Branches take 6 (to test shadow)
+            with m.Elif(self.alu.op >= 4): # Branches take 6 (to test shadow)
                 m.d.sync += self.counter.eq(6)
             with m.Else(): # ADD/SUB to take 2
                 m.d.sync += self.counter.eq(2)
diff --git a/src/experiment/compldst.py b/src/experiment/compldst.py
index 15aebee0..f67d75b0 100644
--- a/src/experiment/compldst.py
+++ b/src/experiment/compldst.py
@@ -172,12 +172,7 @@ class LDSTCompUnit(Elaboratable):
         with m.If(opc_l.qn):
             sync += self.counter.eq(0) # reset counter when not busy
         with m.If(req_l.qn & busy_o & (self.counter == 0)):
-            with m.If(self.oper_i == 2): # MUL, to take 5 instructions
-                sync += self.counter.eq(5)
-            with m.Elif(self.oper_i == 3): # SHIFT to take 7
-                sync += self.counter.eq(7)
-            with m.Else(): # ADD/SUB to take 2
-                sync += self.counter.eq(2)
+            sync += self.counter.eq(2) # take 2 (fake) cycles to respond
         with m.If(self.counter > 1):
             sync += self.counter.eq(self.counter - 1)
         with m.If(self.counter == 1):