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

Subversion Repositories lcd_block

[/] [lcd_block/] [trunk/] [hdl/] [iseProject/] [lcd_controller.v] - Blame information for rev 5

Go to most recent revision | Details | Compare with Previous | View Log

Line No. Rev Author Line
1 5 leonardoar 
`timescale 1ns / 1ps
2 
 
3 
module lcd_controller(
4 
    input rst,
5 
    input clk,
6 
    input [7:0] data_in,
7 
    input strobe_in,
8 
    input [7:0] period_clk_ns,
9 
    output lcd_e,
10 
    output [3:0] lcd_nibble,
11 
    output lcd_rs,
12 
    output lcd_rw,
13 
    output disable_flash,
14 
    output done
15 
    );
16 
 
17 
        // States for FSM that initialize the LCD
18 
        localparam lcd_init_rst = 1;
19 
        localparam lcd_init_wait = 2;
20 
        localparam lcd_init_write_03_01 = 3;
21 
        localparam lcd_init_wait_4ms = 4;
22 
        localparam lcd_init_write_03_02 = 5;
23 
        localparam lcd_init_wait_100us = 6;
24 
        localparam lcd_init_write_03_03 = 7;
25 
        localparam lcd_init_wait_40us = 8;
26 
        localparam lcd_init_write_02 = 9;
27 
        localparam lcd_init_wait_50us = 10;
28 
        localparam lcd_init_strobe = 11;
29 
        reg [3:0] lcd_init_states, lcd_init_state_next;
30 
        reg [19:0] counter_wait_lcd_init;
31 
        reg [3:0] counter_wait_strobe_lcd_init;
32 
        reg [19:0] time_wait_lcd_init;
33 
        reg [3:0] lcd_init_data_out;
34 
        reg lcd_init_e_out;
35 
 
36 
 
37 
        /*
38 
                Initialize LCD...
39 
        */
40 
        always @ (posedge clk)
41 
        begin
42 
                if (rst)        // Reset synchronous
43 
                        begin
44 
                                lcd_init_states <= lcd_init_rst;
45 
                                counter_wait_lcd_init <= 0;
46 
                                counter_wait_strobe_lcd_init <= 0;
47 
                        end
48 
                else
49 
                        begin
50 
                                case (lcd_init_states)
51 
                                        lcd_init_rst:
52 
                                                begin
53 
                                                        // Wait for 15ms to power-up LCD
54 
                                                        time_wait_lcd_init <= 15000000;
55 
                                                        lcd_init_states <= lcd_init_wait;
56 
                                                        lcd_init_state_next <= lcd_init_write_03_01;
57 
                                                end
58 
 
59 
                                        // Wait for a configured time in (ns) and go to other state in (lcd_init_state_next)
60 
                                        lcd_init_wait:
61 
                                                begin
62 
                                                        counter_wait_lcd_init <= counter_wait_lcd_init + period_clk_ns;
63 
                                                        if (counter_wait_lcd_init > time_wait_lcd_init)
64 
                                                                lcd_init_states <= lcd_init_state_next;
65 
                                                end
66 
 
67 
                                        // Strobe the LCD for at least 240 ns
68 
                                        lcd_init_strobe:
69 
                                                begin
70 
                                                        lcd_init_e_out = 1;
71 
                                                        counter_wait_strobe_lcd_init <= counter_wait_strobe_lcd_init + period_clk_ns;
72 
                                                        if (counter_wait_strobe_lcd_init > 240)
73 
                                                                begin
74 
                                                                        lcd_init_states <= lcd_init_state_next;
75 
                                                                        lcd_init_e_out <= 0;
76 
                                                                end
77 
                                                end
78 
 
79 
                                        lcd_init_write_03_01:
80 
                                                // Send 0x3 and pulse LCD_E for 240ns
81 
                                                begin
82 
                                                        lcd_init_data_out <= 4'h3;
83 
                                                        lcd_init_states <= lcd_init_strobe;     // Strobe for at least 230 ns
84 
                                                        lcd_init_state_next <= lcd_init_wait_4ms;
85 
                                                end
86 
 
87 
                                        lcd_init_wait_4ms:
88 
                                                begin
89 
                                                        time_wait_lcd_init <= 4100000;  // Wait for 4.1ms
90 
                                                        lcd_init_states <= lcd_init_wait;
91 
                                                        lcd_init_state_next <= lcd_init_write_03_02;
92 
                                                end
93 
 
94 
                                        lcd_init_write_03_02:
95 
                                                // Send 0x3 and pulse LCD_E for 240ns
96 
                                                begin
97 
                                                        lcd_init_data_out <= 4'h3;
98 
                                                        lcd_init_states <= lcd_init_strobe;     // Strobe for at least 230 ns
99 
                                                        lcd_init_state_next <= lcd_init_wait_100us;
100 
                                                end
101 
 
102 
                                        lcd_init_wait_100us:
103 
                                                begin
104 
                                                        time_wait_lcd_init <= 100000;   // Wait for 100us
105 
                                                        lcd_init_states <= lcd_init_wait;
106 
                                                        lcd_init_state_next <= lcd_init_write_03_03;
107 
                                                end
108 
 
109 
                                        lcd_init_write_03_03:
110 
                                                // Send 0x3 and pulse LCD_E for 240ns
111 
                                                begin
112 
                                                        lcd_init_data_out <= 4'h3;
113 
                                                        lcd_init_states <= lcd_init_strobe;     // Strobe for at least 230 ns
114 
                                                        lcd_init_state_next <= lcd_init_wait_40us;
115 
                                                end
116 
 
117 
                                        lcd_init_wait_40us:
118 
                                                begin
119 
                                                        time_wait_lcd_init <= 100000;   // Wait for 100us
120 
                                                        lcd_init_states <= lcd_init_wait;
121 
                                                        lcd_init_state_next <= lcd_init_write_02;
122 
                                                end
123 
 
124 
                                        lcd_init_write_02:
125 
                                                // Send 0x3 and pulse LCD_E for 240ns
126 
                                                begin
127 
                                                        lcd_init_data_out <= 4'h2;
128 
                                                        lcd_init_states <= lcd_init_strobe;     // Strobe for at least 230 ns
129 
                                                        lcd_init_state_next <= lcd_init_wait_50us;
130 
                                                end
131 
 
132 
                                        lcd_init_wait_50us:
133 
                                                begin
134 
                                                        time_wait_lcd_init <= 100000;   // Wait for 100us
135 
                                                        lcd_init_states <= lcd_init_wait;
136 
                                                        lcd_init_state_next <= lcd_init_write_02;
137 
                                                end
138 
                                endcase;
139 
                        end;
140 
        end;
141 
 
142 
        assign lcd_e = lcd_init_e_out;
143 
        assign lcd_nibble = lcd_init_data_out;
144 
 
145 
endmodule

powered by: WebSVN 2.1.0

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