1 files changed, 10 insertions, 5 deletions

diff --git a/rtl/lisp_coproc.sv b/rtl/lisp_coproc.sv
index b855b7b..6bd8574 100644
--- a/rtl/lisp_coproc.sv
+++ b/rtl/lisp_coproc.sv
@@ -1,3 +1,5 @@
+`timescale 1ns/1ps // be consistent with testbench
+
 module lisp_coproc (
     input  wire        clk,
     input  wire        rst,
@@ -33,7 +35,6 @@ module lisp_coproc (
     
     // Type Checkers
     wire is_cons_a   = (arg1_reg[7:6] == 2'b11);
-    wire is_cons_b   = (arg2_reg[7:6] == 2'b11);
     wire is_num_a    = (arg1_reg[7:6] == 2'b10);
     wire is_num_b    = (arg2_reg[7:6] == 2'b10);
     
@@ -99,10 +100,11 @@ module lisp_coproc (
             // --- MMIO Writes ---
             if (cs && !rw) begin
                 case (addr)
-                    3'h0: opcode_reg <= data_in;
-                    3'h1: arg1_reg   <= data_in;
-                    3'h2: arg2_reg   <= data_in;
-                    3'h3: result_reg <= data_in;
+                  3'h0: opcode_reg <= data_in;
+                  3'h1: arg1_reg   <= data_in;
+                  3'h2: arg2_reg   <= data_in;
+                  3'h3: result_reg <= data_in;
+                  default: ;
                 endcase
             end
             
@@ -157,6 +159,7 @@ module lisp_coproc (
                                 if (alu_sum[5:0] == 6'd0) flag_zero <= 1'b1;
                             end
                         end
+                      default: ;
                     endcase
                 end
 
@@ -183,8 +186,10 @@ module lisp_coproc (
                         8'h06: begin // ADD
                             if (!flag_err_type) result_reg <= {2'b10, alu_sum[5:0]};
                         end
+                      default: ;
                     endcase
                 end
+              default: ;
             endcase
         end
     end