From 37db52dbd66db1fd43337082249c469eda39f776 Mon Sep 17 00:00:00 2001 From: Nick McKinney Date: Thu, 1 Dec 2016 21:36:51 -0600 Subject: initial commit --- alu.v | 68 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 68 insertions(+) create mode 100644 alu.v (limited to 'alu.v') diff --git a/alu.v b/alu.v new file mode 100644 index 0000000..1ecc0a0 --- /dev/null +++ b/alu.v @@ -0,0 +1,68 @@ +module alu ( + input [3:0] op, + input [15:0] x, + input [15:0] y, + output [15:0] result, + output zero, + output carry +); + +// op: +// 0000: result = x + y +// 0001: result = x - y +// 0010: result = x * y +// 0011: result = x / y +// 0100: result = x & y +// 0101: result = x | y +// 0110: result = x ^ y +// 0111: result = don't care +// 1000: result = x << y (zero extend) +// 1001: result = x << y (one extend) +// 1010: result = x << y (extend with last bit) +// 1011: result = x << y (barrel shift) +// 1100: result = x >> y (zero extend) +// 1101: result = x >> y (one extend) +// 1110: result = x >> y (extend with sign bit) +// 1111: result = x >> y (barrel shift) + + wire [16:0] sum; + wire [16:0] diff; + wire [16:0] prod; + wire [16:0] quot; + wire [15:0] anded; + wire [15:0] ored; + wire [15:0] xored; + wire [15:0] shifted; + + assign sum = x + y; + assign diff = x - y; + assign prod = x * y; + assign quot = x / y; + assign anded = x & y; + assign ored = x | y; + assign xored = x ^ y; + + shifter shifter_inst ( + .v(x), + .by(y), + .dir(op[2]), + .extend(op[1:0]), + .result(shifted) + ); + + assign result = + op == 4'b0000 ? sum[15:0] : + op == 4'b0001 ? diff[15:0] : + op == 4'b0010 ? prod[15:0] : + op == 4'b0011 ? quot[15:0] : + op == 4'b0100 ? anded : + op == 4'b0101 ? ored : + op == 4'b0110 ? xored : + shifted; + + assign zero = ~(|result); + assign carry = + op == 4'b0000 ? sum[16] : + op == 4'b0001 ? diff[16] : 1'b0; + +endmodule -- cgit v1.2.3