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/*
* lcd44780.c
* Simple "driver" for a memory-mapped 44780-style LCD display.
*
* Copyright 2001 Bradley D. LaRonde <brad@ltc.com>
*
* This program is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License as published by the
* Free Software Foundation; either version 2 of the License, or (at your
* option) any later version.
*
*/
#define LCD44780_COMMAND ((volatile unsigned char *)0xbe020000)
#define LCD44780_DATA ((volatile unsigned char *)0xbe020001)
#define LCD44780_4BIT_1LINE 0x20
#define LCD44780_4BIT_2LINE 0x28
#define LCD44780_8BIT_1LINE 0x30
#define LCD44780_8BIT_2LINE 0x38
#define LCD44780_MODE_DEC 0x04
#define LCD44780_MODE_DEC_SHIFT 0x05
#define LCD44780_MODE_INC 0x06
#define LCD44780_MODE_INC_SHIFT 0x07
#define LCD44780_SCROLL_LEFT 0x18
#define LCD44780_SCROLL_RIGHT 0x1e
#define LCD44780_CURSOR_UNDERLINE 0x0e
#define LCD44780_CURSOR_BLOCK 0x0f
#define LCD44780_CURSOR_OFF 0x0c
#define LCD44780_CLEAR 0x01
#define LCD44780_BLANK 0x08
#define LCD44780_RESTORE 0x0c // Same as CURSOR_OFF
#define LCD44780_HOME 0x02
#define LCD44780_LEFT 0x10
#define LCD44780_RIGHT 0x14
void lcd44780_wait(void)
{
int i, j;
for(i=0; i < 400; i++)
for(j=0; j < 10000; j++);
}
void lcd44780_command(unsigned char c)
{
*LCD44780_COMMAND = c;
lcd44780_wait();
}
void lcd44780_data(unsigned char c)
{
*LCD44780_DATA = c;
lcd44780_wait();
}
void lcd44780_puts(const char* s)
{
int j;
int pos = 0;
lcd44780_command(LCD44780_CLEAR);
while(*s) {
lcd44780_data(*s);
s++;
pos++;
if (pos == 8) {
/* We must write 32 of spaces to get cursor to 2nd line */
for (j=0; j<32; j++) {
lcd44780_data(' ');
}
}
if (pos == 16) {
/* We have filled all 16 character positions, so stop
outputing data */
break;
}
}
#ifdef LCD44780_PUTS_PAUSE
{
int i;
for(i = 1; i < 2000; i++)
lcd44780_wait();
}
#endif
}
void lcd44780_init(void)
{
// The display on the RockHopper is physically a single
// 16 char line (two 8 char lines concatenated). bdl
lcd44780_command(LCD44780_8BIT_2LINE);
lcd44780_command(LCD44780_MODE_INC);
lcd44780_command(LCD44780_CURSOR_BLOCK);
lcd44780_command(LCD44780_CLEAR);
}
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