-
Notifications
You must be signed in to change notification settings - Fork 0
/
timing_control.sv
88 lines (81 loc) · 2.87 KB
/
timing_control.sv
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
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
`timescale 1ns / 1ps
//////////////////////////////////////////////////////////////////////////////////
// Company:
// Engineer:
//
// Create Date: 11/01/2021 12:59:03 PM
// Design Name:
// Module Name: timing_control
// Project Name:
// Target Devices:
// Tool Versions:
// Description:
//
// Additional Comments: Copyright (C) 2021 Jonathan Stein (New York, USA)
//
// "MIT License"
//
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the "Software"), to deal
// in the Software without restriction, including without limitation the rights
// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
// copies of the Software, and to permit persons to whom the Software is
// furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included in all
// copies or substantial portions of the Software with full atribution, i.e.,
// clearly identifying the author such that the average, ordinary person using
// this work would be on notice as to the author of this work, as well as understanding
// the terms of this license, as set forth herein.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
// SOFTWARE.
//
// Feel free to contact the author through the 6502 user forum:
// http://forum.6502.org/memberlist.php?mode=viewprofile&u=3597
//
//
//////////////////////////////////////////////////////////////////////////////////
module timing_control(
input logic reset,
output logic tc_to_id,
input cg_to_tc,
input logic phi2_in,
output logic phi2_out,
input logic fclk,
input logic sfclk,
output logic [3:0] r,
output logic [1:0] q,
output logic p,
output logic fclk_out
);
logic [1:0] q_step = 0;
logic p_step = 0;
logic [3:0] r_step = 4'b0010;
assign phi2_out = phi2_in;
assign q = q_step;
assign p = p_step;
assign r = r_step;
assign fclk_out = fclk;
always @(posedge fclk) begin
if (q_step == 2'b11)
p_step <= 0;
else if (q_step == 2'b01)
p_step <= 1;
q_step <= q_step + 2'b01;
if (reset) begin
q_step <= 0;
p_step <= 0;
end
end
always @(posedge sfclk) begin
r_step <= r_step + 4'b0001;
if (reset)
r_step <= 4'b0001;
end
endmodule