lcd_drv.c

MP3播放器详细设计方案

/*C**************************************************************************
* $RCSfile: lcd_drv.c,v $
*----------------------------------------------------------------------------
* Copyright (c) 2002 Atmel.
*----------------------------------------------------------------------------
* RELEASE:      $Name: DEMO_FAT_1_9_9 $      
* REVISION:     $Revision: 1.5 $     
* FILE_CVSID:   $Id: lcd_drv.c,v 1.5 2002/05/24 09:51:15 njourdan Exp $       
*----------------------------------------------------------------------------
* PURPOSE:
* This file contains the 8-bit lcd driver routines
*
* NOTES:
* Driver Configuration:
*   - LCD_CMD_ADD in board.h
*   - LCD_DAT_ADD in board.h
*   - FPER defined in config.h
* Global Variables:
*   - None
*****************************************************************************/

/*_____ I N C L U D E S ____________________________________________________*/

#include "config.h"                         /* lib configuration header */
#include "..\board.h"                       /* board definition */
#include "lcd_drv.h"                        /* lcd driver definition */

/*_____ M A C R O S ________________________________________________________*/


/*_____ D E F I N I T I O N ________________________________________________*/

xdata   Byte lcd_cmd At(LCD_CMD_ADD);
xdata   Byte lcd_data At(LCD_DAT_ADD);

static  Byte    lcd_line;               /* save the cursor position */

/*_____ D E C L A R A T I O N ______________________________________________*/

static  void    lcd_wr_cmd (char);
static  void    lcd_wr_data (char);


/*F**************************************************************************
* NAME: lcd_init
*----------------------------------------------------------------------------
* PARAMS:
*
* return:
*----------------------------------------------------------------------------
* PURPOSE: 
*   LCD controller initialization and configuration
*----------------------------------------------------------------------------
* EXAMPLE:
*----------------------------------------------------------------------------
* NOTE:
*   This function is called once to initialize the LCD display
*----------------------------------------------------------------------------
* REQUIREMENTS:
*****************************************************************************/
void lcd_init (void)
{
Uint16  data  i;

  for (i = 0; i < TEMPO_30MS; i++);     /* initialization delay */

  lcd_wr_cmd(LCD_FCTSET | LCD_8BIT | LCD_2_LINE | LCD_5x8DOTS);
  lcd_wr_cmd(LCD_DISPLAY | LCD_DISP_ON | LCD_CURS_OFF | LCD_BLINK_OFF);
  lcd_wr_cmd(LCD_SET | LCD_INC | LCD_RIGHT);
  lcd_wr_cmd(LCD_CLR);
  for (i = 0; i < TEMPO_1_5MS; i++);    /* clear delay */
  lcd_line = LCD_LINE0;
}


/*F**************************************************************************
* NAME: lcd_clr
*----------------------------------------------------------------------------
* PARAMS:
*
* return:
*----------------------------------------------------------------------------
* PURPOSE: 
*   Clear display and set cusor to home
*----------------------------------------------------------------------------
* EXAMPLE:
*----------------------------------------------------------------------------
* NOTE:
*   No delay is performed, it is to the attention of the user to take care
*   of the clear time
*----------------------------------------------------------------------------
* REQUIREMENTS:
*****************************************************************************/
void lcd_clr (void)
{
  lcd_wr_cmd(LCD_CLR);
  lcd_line = LCD_LINE0;
}


/*F**************************************************************************
* NAME: lcd_set_cur
*----------------------------------------------------------------------------
* PARAMS:
*   line:   LCD_LINE0: cursor on line 0
*           LCD_LINE1: cursor on line 1
*   column: column number of the new position of the cursor
*
* return:
*----------------------------------------------------------------------------
* PURPOSE: 
*   Set the cursor position
*----------------------------------------------------------------------------
* EXAMPLE:
*----------------------------------------------------------------------------
* NOTE:
*   Columns start from 0 (LCD_LINE0, 0) is home
*----------------------------------------------------------------------------
* REQUIREMENTS:
*****************************************************************************/
void lcd_set_cur (Byte line, Byte column)
{
  lcd_line = line;                      /* update the line position */
  lcd_wr_cmd(line | column);            /* write the new cursor position */
}


/*F**************************************************************************
* NAME: lcd_putchar
*----------------------------------------------------------------------------
* PARAMS:
*   c: character to display
*
* return:
*----------------------------------------------------------------------------
* PURPOSE: 
*   LCD display interpreter
*----------------------------------------------------------------------------
* EXAMPLE:
*----------------------------------------------------------------------------
* NOTE:
*----------------------------------------------------------------------------
* REQUIREMENTS:
*****************************************************************************/
void lcd_putchar (char c)
{
  switch (c)
  {
    case C_R:                   /* Carriage Return */
    {
      lcd_set_cur(lcd_line, 0);
      break;
    }

    case L_F:                   /* Line Feed + Carriage Return */
    {
      lcd_set_cur((lcd_line + LCD_LINE_OFFSET), 0);
      break;
    }

    default:
    {
      lcd_wr_data(c);           /* write the character to the display */
      break;
    }
  }
}


/*F**************************************************************************
* NAME: lcd_wr_cmd
*----------------------------------------------------------------------------
* PARAMS:
*   cmd: command to write on the LCD driver
*
* return:
*----------------------------------------------------------------------------
* PURPOSE: 
*   Write command on LCD 
*----------------------------------------------------------------------------
* EXAMPLE:
*----------------------------------------------------------------------------
* NOTE:
*----------------------------------------------------------------------------
* REQUIREMENTS:
*****************************************************************************/
void lcd_wr_cmd (char cmd)
{
Byte  data  i;

  lcd_cmd = cmd;
  for (i = 0; i < TEMPO_40US; i++);
}


/*F**************************************************************************
* NAME: lcd_wr_data
*----------------------------------------------------------------------------
* PARAMS:
*   dat: data to write on the LCD driver
*
* return:
*----------------------------------------------------------------------------
* PURPOSE: 
*   Write data on LCD
*----------------------------------------------------------------------------
* EXAMPLE:
*----------------------------------------------------------------------------
* NOTE:
*----------------------------------------------------------------------------
* REQUIREMENTS:
*****************************************************************************/
void lcd_wr_data (char dat)
{
Byte  data  i;

  lcd_data = dat;
  for (i = 0; i < TEMPO_40US - 4; i++);
}


/*F**************************************************************************
* NAME: lcd_wr_cgram
*----------------------------------------------------------------------------
* PARAMS:
*   dat: data to write on the LCD driver
*
* return:
*----------------------------------------------------------------------------
* PURPOSE: 
*   Write data on LCD CGRAM
*----------------------------------------------------------------------------
* EXAMPLE:
*----------------------------------------------------------------------------
* NOTE:
*----------------------------------------------------------------------------
* REQUIREMENTS:
*****************************************************************************/
void lcd_wr_cgram (char dat)
{
Byte  data  i;

  lcd_data = dat;
  for (i = 0; i < TEMPO_40US; i++);
}


/*F**************************************************************************
* NAME: lcd_cgram
*----------------------------------------------------------------------------
* PARAMS:
*   address:    character address in cgram
*   pt_pattern: pointer on pattern in code segment
*
* return:
*----------------------------------------------------------------------------
* PURPOSE: 
*   LCD controller Character Graphic RAM set-up
*----------------------------------------------------------------------------
* EXAMPLE:
*----------------------------------------------------------------------------
* NOTE:
*   This function is called to re-define a graphic character
*   The HD44780 controller contains 8 locations in RAM where user's
*   characters can be defined
*----------------------------------------------------------------------------
* REQUIREMENTS:
*****************************************************************************/
void lcd_cgram (Byte address, Byte code *pt_pattern)
{

  lcd_wr_cmd(LCD_CGRAM | address);      /* select character in graphic RAM */

  lcd_wr_cgram(pt_pattern[0]);          /* load symbols */
  lcd_wr_cgram(pt_pattern[1]);
  lcd_wr_cgram(pt_pattern[2]);
  lcd_wr_cgram(pt_pattern[3]);
  lcd_wr_cgram(pt_pattern[4]);
  lcd_wr_cgram(pt_pattern[5]);
  lcd_wr_cgram(pt_pattern[6]);
  lcd_wr_cgram(pt_pattern[7]);

  lcd_wr_cmd(lcd_line);                 /* select display data RAM */
}