blob: 1474d6da22659a9f46a8dfbce3b2e7d571111b83 (
plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
|
// represents the Ben Eater 8bit computer - ALU
`timescale 1us/1us
module eater_alu (
input wire clk_in,
input wire en_output_in,
input wire subtract_n_add_in,
input wire [7:0] A_in,
input wire [7:0] B_in,
output wire [7:0] bus_out
);
wire [7:0] result = subtract_n_add_in ? (A_in - B_in) : (A_in + B_in);
// wire [7:0] xormask = {8{subtract_n_add_in}};
// wire [7:0] B_neg_if = B_in ^ xormask;
// wire [7:0] result2 = A_in + B_neg_if + subtract_n_add_in;
assign bus_out = en_output_in ? result : 8'bz;
endmodule
|
