opb_lcd_controller.c

spartan3系列fpga opb模式下lcd液晶屏控制代码

//////////////////////////////////////////////////////////////////////////////
//
// ***************************************************************************
// **                                                                       **
// ** Copyright (c) 2004 Xilinx, Inc. All Rights Reserved.                  **
// **                                                                       **
// ** You may copy and modify these files for your own internal use solely  **
// ** with Xilinx programmable logic devices and Xilinx EDK system or       **
// ** create IP modules solely for Xilinx programmable logic devices and    **
// ** Xilinx EDK system. No rights are granted to distribute any files      **
// ** unless they are distributed in Xilinx programmable logic devices.     **
// **                                                                       **
// ***************************************************************************
//
//////////////////////////////////////////////////////////////////////////////
// Filename:          D:\Data\ppc_espw_opb_mem_controller_custom_ip\drivers\opb_lcd_controller_v1_00_a\src\opb_lcd_controller.c
// Version:           1.00.a
// Description:       opb_lcd_controller Driver Source File
// Date:              Sat Aug 21 11:28:31 2004 (by Create and Import Peripheral Wizard)
//////////////////////////////////////////////////////////////////////////////


/***************************** Include Files *******************************/

#include "opb_lcd_controller.h"

/************************** Function Definitions ***************************/

/******************************************************************************
* Function name         :  lcd.c
* returns               :  
* Created by            :  Nasser Poureh 
* Date Created          :  10/25/02
* Company				:  Insight Electronics
* Description           :  lcd driver
* Notes                 :  
******************************************************************************/


//	The following function generates a variable delay

void _wait(loop_count)
int	loop_count;
{

int	sum, data;

sum	= 0;

for (data = 0; data < loop_count; data++) {
	sum = (data << 8);
}
  return;
}




//	The following function write a byte of data to the lcd panel according
//	to the following table:
//
//	mode		operation performed
//	-----------------------------------------------------------------------
//	0		write to the lcd control register
//	1		read from lcd control register (not used)
//	2		write to the lcd data register
//	3		read from lcd data registre (not used)
//
//	It should be noted that the MBS of node is used as the lcd_rs signal,
//	while the LSB of the mode is used as the lcd_rw signal. Hence, mode
//	and 8 bits of data are used to form a 10-bit quantity that will be
//	writen to the lcd panel over the OPB data bus.

void display_update(base_addr, data, mode)
char	data;
int		mode;
unsigned int base_addr;

{
		int	lcd_control_data, extended_mode, extended_data, lcd_data_read;
		unsigned int* lcd_location = (unsigned int *) base_addr;

		extended_mode = (mode << 8) & 0x00000300;
		extended_data = data & 0x000000ff;
		lcd_control_data = extended_mode | extended_data;
		*lcd_location = lcd_control_data;
		_wait(5000);
		 return;
}






//	The following function performs the lcd initializations. This function most
//	be called in the main program before any access to the lcd panel is performed.

void lcd_init(base_addr)
	unsigned int base_addr;

{
	int lcd_count;
	static char lcd_data_init[6] =	{0x38, 0x06, 0x0e, 0x01, 0x80, 0x0c};

	_wait(150000);

	for (lcd_count = 0; lcd_count < 6; lcd_count++) {
		display_update(base_addr, (lcd_data_init[lcd_count]), 0);
		_wait(500000);
	}
	_wait(500000);
	return;
}




//	This function is used to write a string of characters to the lcd panel.

void lcd_write(unsigned int base_addr, char *s)
{
  while (*s)
  {
	display_update(base_addr, *s, 2);
    s++;
  }
	return;
}




//	The following function is used to clear the lcd panel.

void lcd_clear(base_addr)
	unsigned int base_addr;
{
	display_update(base_addr, 0x01, 0);
	return;
}





//	The following function is used to select which line os the lcd is being
//	writen to (line 1 or 2).

void lcd_line(base_addr, line)
	unsigned int base_addr;
	int line;
{
	switch (line)
	{
	case 1:	display_update(base_addr, 0x80, 0);
			break;
	case 2:	display_update(base_addr, 0xc0, 0);
			break;
      default:
                	display_update(base_addr, 0x80, 0);
			break;
	}
	return;
}