4 files changed, 26 insertions, 18 deletions
diff --git a/eater_cpu/Makefile b/eater_cpu/Makefile
index c39f541..2a958de 100644
--- a/eater_cpu/Makefile
+++ b/eater_cpu/Makefile
@@ -1,2 +1,2 @@
-cpu: eater_computer_tb.sv eater_computer.sv bus_writer.sv eater_register.v  eater_alu.sv  ../playground/my_mem.v  ../nandgame/counter.sv
+cpu: eater_computer_tb.sv eater_computer.sv zbuffer.sv eater_register.v  eater_alu.sv  ../playground/my_mem.v  ../nandgame/counter.sv
 	iverilog -o $@ -g2012  $^
diff --git a/eater_cpu/bus_writer.sv b/eater_cpu/bus_writer.sv
deleted file mode 100644
index fe34202..0000000
--- a/eater_cpu/bus_writer.sv
+++ /dev/null
@@ -1,13 +0,0 @@
-// Debugging the Ben Eater bus, by manually writing data to it.
-
-`timescale 1us/1us
-
-module bus_writer (
-    input wire [7:0] in_value,
-    input wire in_write_to_output,
-    output wire [7:0] out_value
-);
-
-assign out_value = in_write_to_output ? in_value : 8'bZ;
-
-endmodule
diff --git a/eater_cpu/eater_computer_tb.sv b/eater_cpu/eater_computer_tb.sv
index d05dc52..74ffb8a 100644
--- a/eater_cpu/eater_computer_tb.sv
+++ b/eater_cpu/eater_computer_tb.sv
@@ -14,10 +14,10 @@ eater_computer uut (
 logic [7:0] debug_value;
 logic debug_enable;
 
-bus_writer debugger (
-  .in_value(debug_value),
-  .in_write_to_output(debug_enable),
-  .out_value(uut.bus)
+zbuffer debugger (
+  .data_in(debug_value),
+  .en_output_in(debug_enable),
+  .data_out(uut.bus)
 );
 
 initial begin
diff --git a/eater_cpu/zbuffer.sv b/eater_cpu/zbuffer.sv
new file mode 100644
index 0000000..fd7e0f6
--- /dev/null
+++ b/eater_cpu/zbuffer.sv
@@ -0,0 +1,21 @@
+`timescale 1us/1us
+
+`ifndef ZBUFFER
+`define ZBUFFER
+
+module zbuffer #(
+  parameter BUFFER_WIDTH = 8
+) (
+  // async - output data
+  input wire en_output_in,
+
+  input wire [(BUFFER_WIDTH-1) : 0] data_in,
+  // output (to bus) if output enabled.
+  output wire [(BUFFER_WIDTH-1) : 0] data_out
+);
+
+assign data_out = en_output_in ? data_in : {BUFFER_WIDTH{1'bz}};
+
+endmodule
+
+`endif