OpenCores
URL https://opencores.org/ocsvn/s80186/s80186/trunk

Subversion Repositories s80186

[/] [s80186/] [trunk/] [rtl/] [alu/] [ror.sv] - Blame information for rev 2

Details | Compare with Previous | View Log

Line No. Rev Author Line
1 2 jamieiles
// Copyright Jamie Iles, 2017
2
//
3
// This file is part of s80x86.
4
//
5
// s80x86 is free software: you can redistribute it and/or modify
6
// it under the terms of the GNU General Public License as published by
7
// the Free Software Foundation, either version 3 of the License, or
8
// (at your option) any later version.
9
//
10
// s80x86 is distributed in the hope that it will be useful,
11
// but WITHOUT ANY WARRANTY; without even the implied warranty of
12
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
13
// GNU General Public License for more details.
14
//
15
// You should have received a copy of the GNU General Public License
16
// along with s80x86.  If not, see .
17
 
18
task do_ror;
19
    output [31:0] out;
20
    input is_8_bit;
21
    input [15:0] a;
22
    input [4:0] shift_count;
23
    input [15:0] flags_in;
24
    output [15:0] flags_out;
25
    output busy;
26
    input multibit_shift;
27
 
28
    begin
29
        flags_out = flags_in;
30
        out = {11'b0, shift_count, a};
31
 
32
        if (|shift_count || !multibit_shift) begin
33
            if (!is_8_bit) begin
34
                flags_out[CF_IDX] = a[0];
35
                out[15:0] = {a[0], out[15:1]};
36
            end else begin
37
                flags_out[CF_IDX] = a[0];
38
                out[7:0] = {a[0], out[7:1]};
39
            end
40
 
41
            flags_out[OF_IDX] = is_8_bit ? a[7] ^ a[0] : a[15] ^ a[0];
42
            shift_flags(flags_out, is_8_bit, out[15:0], a);
43
 
44
            out[31:16] = {11'b0, shift_count - 1'b1};
45
        end
46
 
47
        busy = multibit_shift && |out[20:16];
48
    end
49
endtask

powered by: WebSVN 2.1.0

© copyright 1999-2024 OpenCores.org, equivalent to Oliscience, all rights reserved. OpenCores®, registered trademark.