tr220flash.c

串行 flash 存储器 SST25VFxxx 芯片接口控制程序

/* common macro & function */
#include "Tr220com.h"

unsigned char ucFlash_Status=0xFF;

/************************************************************************/
/* PROCEDURE: vSST25_Init							*/
/*									*/
/* This procedure initializes the SCK to low. Must be called prior to 	*/
/* setting up mode 0.							*/
/*									*/
/* Input:								*/
/*		None							*/
/*									*/
/* Output:								*/
/*		SCK							*/
/************************************************************************/
void vSST25_Init(void)
{
	
	m25VF020_SCK_OFF;	/* set clock to low initial state */
	
				asm("	nop 				   	  ");
				asm("	nop 				   	  ");
				asm("	nop 				   	  ");
				
				asm("	nop 				   	  ");
				asm("	nop 				   	  ");
				asm("	nop 				   	  ");
		
}

/************************************************************************/
/* PROCEDURE: vSST25_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 vSST25_Send_Byte(unsigned char out)
{
	
	unsigned char i = 0;
	
	for (i = 0; i < 8; i++)
	{
		
		if ((out & 0x80) == 0x80)	/* check if MSB is high */
			{
				m25VF020_SI_ON;
				
				asm("	nop 				   	  ");
				asm("	nop 				   	  ");
				asm("	nop 				   	  ");
				
				
		
			}
		else
			{
				m25VF020_SI_OFF;			/* if not, set to low */
				
				asm("	nop 				   	  ");
				asm("	nop 				   	  ");
				asm("	nop 				   	  ");
		
			}
		
		m25VF020_SCK_OFF;			/* toggle clock low */	
				
				asm("	nop 				   	  ");
				asm("	nop 				   	  ");
				asm("	nop 				   	  ");
		
		m25VF020_SCK_ON;			/* toggle clock high */
						
				asm("	nop 				   	  ");
				asm("	nop 				   	  ");
				asm("	nop 				   	  ");
		
		out = (out << 1);		/* shift 1 place for next bit */
		
	}
	
}

/************************************************************************/
/* PROCEDURE: ucSST25_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 ucSST25_Get_Byte(void)
{
	unsigned char i = 0, in = 0xff;
	for (i = 0; i < 8; i++)
	{
		m25VF020_SCK_OFF;			/* toggle clock low */
					
				asm("	nop 				   	  ");
				asm("	nop 				   	  ");
				asm("	nop 				   	  ");
		
		in = (in << 1);		/* shift 1 place to the left or shift in 0 */
		asm("	mvmd	SPSD1,_iBsp1_in		");
		if((m25VF020_Data_In)==0x00)in=in & 0xfe;
        else in=in | 0x01;
        
				asm("	nop 				   	  ");
				asm("	nop 				   	  ");
				asm("	nop 				   	  ");
        
        m25VF020_SCK_ON;			/* toggle clock high */
		
						
				asm("	nop 				   	  ");
				asm("	nop 				   	  ");
				asm("	nop 				   	  ");
		
	}
	
	in=in & 0xff;	// Add by zhx to meet the char is 16bit character 040730
	
	return in;
}

/************************************************************************/
/* PROCEDURE: vSST25_CE_High							*/
/*									*/
/* This procedure set CE = High.					*/
/*									*/
/* Input:								*/
/*		None							*/
/*									*/
/* Output:								*/
/*		CE							*/
/*									*/
/************************************************************************/
void vSST25_CE_High(void) 
{
	m25VF020_CS_ON;				/* set CE high */
	
		
}


/************************************************************************/
/* PROCEDURE: vSST25_CE_Low							*/
/*									*/
/* This procedure drives the CE of the device to low.  			*/
/*									*/
/* Input:								*/
/*		None							*/
/*									*/
/* Output:								*/
/*		CE							*/
/*									*/
/************************************************************************/
void vSST25_CE_Low(void) 
{	
	m25VF020_CS_OFF;				/* clear CE low */
	
	asm("	nop 				   	  ");
			
		
}


/************************************************************************/
/* PROCEDURE: Read_Status_Register					*/
/*									*/
/* This procedure read the status register and returns the byte.	*/
/*									*/
/* Input:								*/
/*		None							*/
/*									*/
/* Returns:								*/
/*		byte							*/
/************************************************************************/
unsigned char Read_Status_Register(void)
{
	unsigned char byte = 0;
	vSST25_CE_Low();			/* enable device */
	vSST25_Send_Byte(0x05);		/* send RDSR command */
	byte = ucSST25_Get_Byte();		/* receive byte */
	vSST25_CE_High();			/* disable device */
	return byte;
}

/************************************************************************/
/* PROCEDURE: EWSR							*/
/*									*/
/* This procedure Enables Write Status Register.  			*/
/*									*/
/* Input:								*/
/*		None							*/
/*									*/
/* Returns:								*/
/*		Nothing							*/
/************************************************************************/
void EWSR(void)
{
	vSST25_CE_Low();			/* enable device */
	vSST25_Send_Byte(0x50);		/* enable writing to the status register */
	vSST25_CE_High();			/* disable device */
	
}

/************************************************************************/
/* PROCEDURE: WRSR							*/
/*									*/
/* This procedure writes a byte to the Status Register.			*/
/*									*/
/* Input:								*/
/*		byte							*/
/*									*/
/* Returns:								*/
/*		Nothing							*/
/************************************************************************/
void WRSR(unsigned char byte)
{

	vSST25_CE_Low();			/* enable device */
	vSST25_Send_Byte(0x01);		/* select write to status register */
	vSST25_Send_Byte(byte);		/* data that will change the status of BPx 
						or BPL (only bits 2,3,7 can be written) */
	vSST25_CE_High();			/* disable the device */
	
	Wait_Busy();
}

/************************************************************************/
/* PROCEDURE: WREN							*/
/*									*/
/* This procedure enables the Write Enable Latch.			*/
/*									*/
/* Input:								*/
/*		None							*/
/*									*/
/* Returns:								*/
/*		Nothing							*/
/************************************************************************/
void WREN(void)
{
	vSST25_CE_Low();			/* enable device */
	vSST25_Send_Byte(0x06);		/* send WREN command */
	vSST25_CE_High();			/* disable device */
}

/************************************************************************/
/* PROCEDURE: WRDI							*/
/*									*/
/* This procedure disables the Write Enable Latch.			*/
/*									*/
/* Input:								*/
/*		None							*/
/*									*/
/* Returns:								*/
/*		Nothing							*/
/************************************************************************/

/************************************************************************/
/* PROCEDURE: Read_ID							*/
/*									*/
/* This procedure Reads the manufacturer's ID and device ID.  It will 	*/
/* use 90h or ABh as the command to read the ID (90h in this sample).   */