c51源程序sst25vfxxx读写.c

C51 SST 25VF*** 串行FLASH 读写源程序,使用51单片机测试25VF040通过

Functions                    		Function
------------------------------------------------------------------
Read_Status_Register			Reads the status register of the serial flash
EWSR					Enables the Write Status Register
WRSR					Performs a write to the status register
WREN					Write enables the serial flash
WRDI					Write disables the serial flash
Read_ID					Reads the manufacturer ID and device ID
Read					Reads one byte from the serial flash and returns byte
Read_Cont				Reads multiple bytes
Byte_Program				Program one byte to the serial flash
Auto_Add_IncA				Initial Auto Address Increment process
Auto_Add_IncB				Successive Auto_Address_Increment process after AAI initiation
Chip_Erase				Erases entire serial flash
Sector_Erase				Erases one sector (4 KB) of the serial flash
Block_Erase				Erases one block (32 KB) of the serial flash
Wait_Busy				Polls status register until busy bit is low
Wait_Busy_AAI				Polls status register until busy bit is low for AAI programming
WREN_Check				Checks to see if WEL is set
WREN_AAI_Check				Checks to see if WEL and AAI mode is set

"C" LANGUAGE DRIVERS

/********************************************************************/
/* Copyright Silicon Storage Technology, Inc. (SST), 1994-2002	    */
/* Example "C" language Driver of 25VFXXX Serial Flash		    */
/* Aaron Forward, Silicon Storage Technology, Inc.                  */
/*                                                                  */
/* Revision 1.0, April 30th, 2002			  	    */   
/*                                                                  */
/*								    */
/********************************************************************/

#include <stdio.h>
#include <stdlib.h>


/* Function Prototypes */

void init();
void Send_Byte(unsigned char out);
unsigned char Get_Byte();
void CE_High();
void CE_Low();
void Hold();
void Unhold();
void WP();
void UnWP();
unsigned char Read_Status_Register();
void EWSR();
void WRSR(byte);
void WREN();
void WRDI();
unsigned char Read_ID(ID_addr);
unsigned char Read(unsigned long Dst);
void Read_Cont(unsigned long Dst, unsigned long no_bytes);
void Byte_Program(unsigned long Dst, unsigned char byte);
void Auto_Add_IncA(unsigned long Dst, unsigned char byte);
void Auto_Add_IncB(unsigned char byte);
void Chip_Erase();
void Sector_Erase(unsigned long Dst);
void Block_Erase(unsigned long Dst);
void Wait_Busy();
void Wait_Busy_AAI();
void WREN_Check();
void WREN_AAI_Check();


unsigned char idata upper_128[128];	/* global array to store read data */
					/* to upper RAM area from 80H - FFH */

/************************************************************************/
/* PROCEDURE: init							*/
/*									*/
/* This procedure initializes the SCK to low. Must be called prior to 	*/
/* setting up mode 0.							*/
/*									*/
/* Input:								*/
/*		None							*/
/*									*/
/* Output:								*/
/*		SCK							*/
/************************************************************************/
void init()
{
	SCK = 0;	/* set clock to low initial state */
}

/************************************************************************/
/* PROCEDURE: Send_Byte							*/
/*									*/
/* This procedure outputs a byte shifting out 1-bit per clock rising	*/
/* edge on the the SI pin(LSB 1st).					*/
/*									*/
/* Input:								*/
/*		out							*/
/*									*/
/* Output:								*/
/*		SI							*/
/************************************************************************/
void Send_Byte(unsigned char out)
{
	
	unsigned char i = 0;
	for (i = 0; i < 8; i++)
	{
		
		if ((out & 0x80) == 0x80)	/* check if MSB is high */
			SI = 1;
		else
			SI = 0;			/* if not, set to low */
		SCK = 1;			/* toggle clock high */
		out = (out << 1);		/* shift 1 place for next bit */
		SCK = 0;			/* toggle clock low */
	}


}

/************************************************************************/
/* PROCEDURE: Get_Byte							*/
/*									*/
/* This procedure inputs a byte shifting in 1-bit per clock falling	*/
/* edge on the SO pin(LSB 1st).						*/
/*									*/
/* Input:								*/
/*		SO							*/
/*									*/
/* Output:								*/
/*		None							*/
/************************************************************************/
unsigned char Get_Byte()
{
	unsigned char i = 0, in = 0, temp = 0;
	for (i = 0; i < 8; i++)
	{
		in = (in << 1);		/* shift 1 place to the left or shift in 0 */
		temp = SO;		/* save input */
		SCK = 1;		/* toggle clock high */
	if (temp == 1)			/* check to see if bit is high */
		in = in | 0x01;		/* if high, make bit high */

		SCK = 0;		/* toggle clock low */

	}
	return in;
}

/************************************************************************/
/* PROCEDURE: CE_High							*/
/*									*/
/* This procedure set CE = High.					*/
/*									*/
/* Input:								*/
/*		None							*/
/*									*/
/* Output:								*/
/*		CE							*/
/*									*/
/************************************************************************/
void CE_High() 
{
	CE = 1;				/* set CE high */
}


/************************************************************************/
/* PROCEDURE: CE_Low							*/
/*									*/
/* This procedure drives the CE of the device to low.  			*/
/*									*/
/* Input:								*/
/*		None							*/
/*									*/
/* Output:								*/
/*		CE							*/
/*									*/
/************************************************************************/
void CE_Low() 
{	
	CE = 0;				/* clear CE low */
}



/************************************************************************/
/* PROCEDURE: Hold()							*/
/*									*/
/* This procedure clears the Hold pin to low.				*/
/*									*/
/* Input:								*/
/*		None							*/
/*									*/
/* Output:								*/
/*		Hold							*/
/************************************************************************/
void Hold()
{
	Hold = 0;			/* clear Hold pin */
}

/************************************************************************/
/* PROCEDURE: Unhold()							*/
/*									*/
/* This procedure sets the Hold pin to high.				*/
/*									*/
/* Input:								*/
/*		None							*/
/*									*/
/* Output:								*/
/*		Hold							*/
/************************************************************************/
void Unhold()
{
	Hold = 1;			/* set Hold pin */
}

/************************************************************************/
/* PROCEDURE: WP()							*/
/*									*/
/* This procedure clears the WP pin to low.				*/
/*									*/
/* Input:								*/
/*		None							*/
/*									*/
/* Output:								*/
/*		WP							*/
/************************************************************************/
void WP()
{
	WP = 0;				/* clear WP pin */
}

/************************************************************************/
/* PROCEDURE: UnWP()							*/
/*									*/
/* This procedure sets the WP pin to high.				*/
/*									*/
/* Input:								*/
/*		None							*/
/*									*/
/* Output:								*/
/*		WP							*/
/************************************************************************/
void UnWP()
{
	WP = 1;				/* set WP pin */
}

/************************************************************************/
/* PROCEDURE: Read_Status_Register					*/
/*									*/
/* This procedure read the status register and returns the byte.	*/
/*									*/
/* Input:								*/
/*		None							*/
/*									*/
/* Returns:								*/
/*		byte							*/
/************************************************************************/
unsigned char Read_Status_Register()
{
	unsigned char byte = 0;
	CE_Low();			/* enable device */
	Send_Byte(0x05);		/* send RDSR command */
	byte = Get_Byte();		/* receive byte */
	CE_High();			/* disable device */
	return byte;
}

/************************************************************************/
/* PROCEDURE: EWSR							*/
/*									*/
/* This procedure Enables Write Status Register.  			*/
/*									*/
/* Input:								*/
/*		None							*/
/*									*/
/* Returns:								*/
/*		Nothing							*/
/************************************************************************/
void EWSR()
{
	CE_Low();			/* enable device */
	Send_Byte(0x50);		/* enable writing to the status register */
	CE_High();			/* disable device */
}

/************************************************************************/
/* PROCEDURE: WRSR							*/
/*									*/
/* This procedure writes a byte to the Status Register.			*/
/*									*/
/* Input:								*/
/*		byte							*/
/*									*/
/* Returns:								*/
/*		Nothing							*/
/************************************************************************/
void WRSR(byte)
{
	CE_Low();			/* enable device */
	Send_Byte(0x01);		/* select write to status register */
	Send_Byte(byte);		/* data that will change the status of BPx 
						or BPL (only bits 2,3,7 can be written) */
	CE_High();			/* disable the device */
}

/************************************************************************/
/* PROCEDURE: WREN							*/
/*									*/
/* This procedure enables the Write Enable Latch.			*/
/*									*/
/* Input:								*/
/*		None							*/
/*									*/
/* Returns:								*/
/*		Nothing							*/
/************************************************************************/
void WREN()
{
	CE_Low();			/* enable device */
	Send_Byte(0x06);		/* send WREN command */
	CE_High();			/* disable device */
}

/************************************************************************/
/* PROCEDURE: WRDI							*/
/*									*/
/* This procedure disables the Write Enable Latch.			*/
/*									*/
/* Input:								*/
/*		None							*/
/*									*/
/* Returns:								*/
/*		Nothing							*/
/************************************************************************/
void WRDI()
{
	CE_Low();			/* enable device */
	Send_Byte(0x04);		/* send WRDI command */
	CE_High();			/* disable device */
}


/************************************************************************/