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-rw-r--r--alu_stage.v5
-rw-r--r--ctrl_decode.v2
-rw-r--r--ctrl_encode.v2
-rw-r--r--decoder.v2
4 files changed, 5 insertions, 6 deletions
diff --git a/alu_stage.v b/alu_stage.v
index 92c8246..618cc89 100644
--- a/alu_stage.v
+++ b/alu_stage.v
@@ -58,7 +58,7 @@ module alu_stage (
.aluReg1(aluReg1_in),
.aluReg2(aluReg2_in),
.aluOpSource1(aluOpSource1_in), // ALU first operand: 0 = reg, 1 = memory read, 2 = imm8, 3 = PC
- .aluOpSource2(aluOpSource2_in), // ALU second operand: 0 = reg, 1 = ~reg, 2 = PC, 3 = ???
+ .aluOpSource2(aluOpSource2_in), // ALU second operand: 0 = reg, 1 = ???, 2 = PC, 3 = ???
.aluDest(aluDest_in), // 0 = reg, 1 = PC
.aluCarrySource(aluCarrySource), // ALU carry input source: 0 = zero, 1 = one, 2 = carry flag, 3 = inverted carry flag
@@ -83,8 +83,7 @@ module alu_stage (
wire [15:0] aluSrc2;
assign aluSrc2 =
- aluOpSource1_in == 2'h0 ? rf_dataB :
- aluOpSource1_in == 2'h1 ? ~rf_dataIn : pc_in;
+ aluOpSource1_in == 2'h0 ? rf_dataB : pc_in;
assign aluCarry_in = aluCarrySource[0] ^ (aluCarrySource[1] & statusReg[0]);
diff --git a/ctrl_decode.v b/ctrl_decode.v
index 86ecc97..ae861e0 100644
--- a/ctrl_decode.v
+++ b/ctrl_decode.v
@@ -5,7 +5,7 @@ module ctrl_decode (
output [2:0] aluReg1,
output [2:0] aluReg2,
output [1:0] aluOpSource1, // ALU first operand: 0 = reg, 1 = memory read, 2 = imm8, 3 = PC
- output [1:0] aluOpSource2, // ALU second operand: 0 = reg, 1 = ~reg, 2 = PC, 3 = ???
+ output [1:0] aluOpSource2, // ALU second operand: 0 = reg, 1 = ???, 2 = PC, 3 = ???
output aluDest, // 0 = reg, 1 = PC
output [1:0] aluCarrySource, // ALU carry flag input source
diff --git a/ctrl_encode.v b/ctrl_encode.v
index 92ad3c6..be0e385 100644
--- a/ctrl_encode.v
+++ b/ctrl_encode.v
@@ -3,7 +3,7 @@ module ctrl_encode (
input [2:0] aluReg1,
input [2:0] aluReg2,
input [1:0] aluOpSource1, // ALU first operand: 0 = reg, 1 = memory read, 2 = imm8, 3 = PC
- input [1:0] aluOpSource2, // ALU second operand: 0 = reg, 1 = ~reg, 2 = PC, 3 = ???
+ input [1:0] aluOpSource2, // ALU second operand: 0 = reg, 1 = ???, 2 = PC, 3 = ???
input aluDest, // 0 = reg, 1 = PC
input [1:0] aluCarrySource, // ALU carry flag input source
diff --git a/decoder.v b/decoder.v
index 0457640..fc43bbe 100644
--- a/decoder.v
+++ b/decoder.v
@@ -5,7 +5,7 @@ module decoder (
output [2:0] aluReg1,
output [2:0] aluReg2,
output [1:0] aluOpSource1, // ALU first operand: 0 = reg, 1 = memory read, 2 = imm8, 3 = PC
- output [1:0] aluOpSource2, // ALU second operand: 0 = reg, 1 = ~reg, 2 = PC, 3 = ???
+ output [1:0] aluOpSource2, // ALU second operand: 0 = reg, 1 = ???, 2 = PC, 3 = ???
output aluDest, // 0 = reg, 1 = PC
output [1:0] aluCarrySource, // ALU carry input source: 0 = zero, 1 = one, 2 = carry, 3 = ~carry