eater: Use separate "zbuffer" module

keeps code a bit cleaner

1 files changed, 17 insertions, 5 deletions

diff --git a/eater_cpu/eater_computer.sv b/eater_cpu/eater_computer.sv
index 4c59697..4f71f1c 100644
--- a/eater_cpu/eater_computer.sv
+++ b/eater_cpu/eater_computer.sv
@@ -21,7 +21,7 @@ logic A_to_bus, bus_to_A,
       INS_to_bus, bus_to_INS,
       RAM_to_bus, bus_to_RAM,
       ALU_to_bus,
-      PC_to_bus, bus_to_PC,
+      PC_to_bus, bus_to_PC, PC_count_en,
       bus_to_MAR
 ;
 
@@ -90,7 +90,11 @@ my_mem #(
   .async_data_o(RAM_out)
 );
 
-assign bus = RAM_to_bus ? RAM_out : 8'bz;
+zbuffer ram_to_bus_buffer (
+    .data_in(RAM_out),
+    .en_output_in(RAM_to_bus),
+    .data_out(bus)
+);
 
 eater_alu alu (
   .clk_in(clk_in),
@@ -108,11 +112,19 @@ counter #(
   .DATA_WIDTH(4)
 ) PC (
   .clk_in(clk_in),
-  .counter_out(PC_out),
   .X_in(PC_in),
-  .st_store_X_in(bus_to_PC)
+  .st_store_X_in(bus_to_PC),
+  .count_enable_in(PC_count_en),
+  .counter_out(PC_out)
 );
 
-assign bus[3:0] = PC_to_bus ? PC_out[3:0] : 4'bz;
+tri[7:0] PC_out_full;
+assign PC_out_full = {4'b0, PC_out};
+
+zbuffer PC_to_bus_buffer (
+    .data_in(PC_out_full),
+    .en_output_in(PC_to_bus),
+    .data_out(bus)
+);
 
 endmodule