blob: 86b68512fd1cdbdf5fc052411471b4aafa90e309 (
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
25
26
27
28
29
30
31
32
33
|
//
// Copyright 2011 Ettus Research LLC
//
module acc
#(parameter IWIDTH=16, OWIDTH=30)
(input clk,
input clear,
input acc,
input [IWIDTH-1:0] in,
output reg [OWIDTH-1:0] out);
wire [OWIDTH-1:0] in_signext;
sign_extend #(.bits_in(IWIDTH),.bits_out(OWIDTH))
acc_signext (.in(in),.out(in_signext));
// CLEAR & ~ACC --> clears the accumulator
// CLEAR & ACC --> loads the accumulator
// ~CLEAR & ACC --> accumulates
// ~CLEAR & ~ACC --> hold
wire [OWIDTH-1:0] addend1 = clear ? 0 : out;
wire [OWIDTH-1:0] addend2 = ~acc ? 0 : in_signext;
wire [OWIDTH-1:0] sum_int = addend1 + addend2;
always @(posedge clk)
out <= sum_int;
endmodule // acc
|
