Add carry input to ALU

1 files changed, 3 insertions, 0 deletions

diff --git a/decoder.v b/decoder.v
index d6a1e02..3e08df3 100644
--- a/decoder.v
+++ b/decoder.v
@@ -7,6 +7,7 @@ module decoder (
 	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 aluDest,					// 0 = reg, 1 = PC
+	output [1:0] aluCarrySource,	// ALU carry input source: 0 = zero, 1 = one, 2 = carry, 3 = ~carry
 
 	output [2:0] regDest,
 	output regSetH,
@@ -216,6 +217,8 @@ module decoder (
 
 	assign regDest = reg0;
 
+	assign aluCarrySource = 2'h0;
+
 	assign regSetH =
 		instr_mov ? (mov_word | mov_dest_byte_high) :
 		instr_movimm ? movimm_high :