flashdrv.c

AT29C040

/********************************************************************************
Function: 		HZK flash driver file
description: 		
date:  			2004-03-05 
programmer:		 WYS
change:
*******************************************************************************/

#include "backup.h"

void flash_SDP_enable(unsigned char icnum);
void flash_SDP_disable(unsigned char icnum);
void far flash_write_sec(unsigned int sector,unsigned char icnum);
void far flash_read_sec(unsigned int sector,unsigned char icnum);
unsigned char far flash_write(unsigned long addr,unsigned char *str,int length);
void far flash_chip_erase(unsigned char icnum);
void far flash_all_clear(void);

#define BYTES_DIV_SECTOR    		256
#define IC_SECTOR_NUMBER    		2048

/*************************************************************************
* Function: flash software data protection enable
************************************************************/
void flash_SDP_enable(unsigned char icnum)
{
    	unsigned char *ptrfls;
	long addr;

	addr=0x100000;    
	ptrfls = (unsigned char *)(addr+0x5555);
    	*ptrfls = 0xaa;
    	ptrfls = (unsigned char *)(addr+0x2aaa);
    	*ptrfls = 0x55;
    	ptrfls = (unsigned char *)(addr+0x5555);
    	*ptrfls = 0xa0;

}

/*************************************************************************
* Function: flash software data protection disable
* Input: IC chip serial number(0~2)
************************************************************/
void flash_SDP_disable(unsigned char icnum)
{
    unsigned char *ptrfls;
    long addr;
    
	addr=0x100000;    

    ptrfls = (unsigned char *)(addr+0x5555);      //disable command
    *ptrfls = 0xaa;
    ptrfls = (unsigned char *)(addr+0x2aaa);
    *ptrfls = 0x55;
    ptrfls = (unsigned char *)(addr+0x5555);
    *ptrfls = 0x80;
    ptrfls = (unsigned char *)(addr+0x5555);
    *ptrfls = 0xaa;
    ptrfls = (unsigned char *)(addr+0x2aaa);
    *ptrfls = 0x55;
    ptrfls = (unsigned char *)(addr+0x5555);
    *ptrfls = 0x20;
    
}

/*************************************************************************
* Function: write to flash a sector
* Input: sector(the flash sector number 0~2047)
* Input: IC chip serial number(0~2)
* data trans by : flashData[256]
************************************************************/
void far flash_write_sec(unsigned int sector,unsigned char icnum)
{
    unsigned char *ptrfls;
    int i,j;
    long pass;


	asm("\tFCLR	I");				//disable int
	asm("\tNOP");

    flash_SDP_enable(icnum);            //software data protection enable

    pass = (long)sector;
    pass = pass * BYTES_DIV_SECTOR;     //offset in IC
    pass+=0x100000;


    ptrfls = (unsigned char *)pass;
    for(i=0;i<BYTES_DIV_SECTOR;i++)
    {
        ptrfls[i]=flashData[i];         //data writer
    }
	asm("\tNOP");
	asm("\tFSET	I");				//Enable int

	time_ap=30;
	while(time_ap){};		//wait 15ms
	
    
}

/*************************************************************************
* Function: read from flash a sector
* Input: sector(the flash sector number 0~2047)
* Input: IC chip serial number(0~2)
* data trans by : flashData[256]
************************************************************/
void far flash_read_sec(unsigned int sector,unsigned char icnum)
{
    unsigned char *ptrfls;
    int i;
    long pass;

    pass = (long)sector;
    pass = pass * BYTES_DIV_SECTOR;     //offset in IC
    pass+=0x100000;
	
    ptrfls = (unsigned char *)pass;
    for(i=0;i<BYTES_DIV_SECTOR;i++)
    {
        flashData[i]=ptrfls[i];         //data read
    }
}


/*************************************************************************
* Function: write to flash a string
* Input: addr(0x100000~0x27ffff) -> flash absolute address
*        str -> data point
*        length -> data length
************************************************************/
unsigned char far flash_write(unsigned long addr,unsigned char *str,int length)
{
    unsigned char *pstr;
    unsigned char icnum;
    long SecNum;
    int i;
    int j;
    int k;
    int pos;


    pstr = str;

    SecNum = (addr&0x7ffff) >> 8;           //get the flash sector number
    pos = (int)(addr & 0xff);               //get  the offset in the sector
    j=0;                                    //data length
	 
    for(k=0;k<IC_SECTOR_NUMBER;k++)
    {
        flash_read_sec(SecNum,icnum);       //read a sector data to flashData[]

        for(i=pos;i<BYTES_DIV_SECTOR;i++)
        {
        	if(j>=length)            	break;
	        flashData[i] = *pstr++;         //put data that want to writer into flashData[]
       	j++;
       }	
       pos=0;

       flash_write_sec(SecNum,icnum);       //writer a sector data to flash

       if(j>=length)            break;
        SecNum++;
        if(SecNum>=IC_SECTOR_NUMBER)
        {
                break;
        }
    }


    pstr = (unsigned char *)addr;
    for(i=0;i<length;i++)                   //collate data
    {
        if((*pstr)!=(*str))
        {
        	return NG;
	}		
        str++;
        pstr++;
    }
    return OK;
}

/*************************************************************************
* Function: flash chip erase
* Input: IC chip serial number(0~2)
note:
	1)for at29c040, the erase time is 20ms.
	2)the erease result is FF
	3)if boot lockout feature enable, this function can NOT work
************************************************************/
void far flash_chip_erase(unsigned char icnum)
{
    unsigned char *ptrfls;
    long addr;

	addr=0x100000;    
	
 	 ptrfls = (unsigned char *)(addr+0x5555);        //chip erase comand
        *ptrfls = 0xaa;
        ptrfls = (unsigned char *)(addr+0x2aaa);
        *ptrfls = 0x55;
        ptrfls = (unsigned char *)(addr+0x5555);
        *ptrfls = 0x80;
        ptrfls = (unsigned char *)(addr+0x5555);
        *ptrfls = 0xaa;
        ptrfls = (unsigned char *)(addr+0x2aaa);
        *ptrfls = 0x55;
        ptrfls = (unsigned char *)(addr+0x5555);
        *ptrfls = 0x10;

    time_ap=60;
    while(time_ap);	//max.30ms delay
    
}