|
|
|
|
|
| |
| AT45DB041读写程序 |
| *正常操作电压为2.7~3.6V,实验中发现当电压超过4.25V后读出的状态字节为9A（正常 */
/*的状态字节值为9D）,并且读写数据均不准确,所以应当保证卡片的供电电压不超过 */
/*4.25V。 */
/*SPI规范：Data is always clocked into the device on the rising edge of SCK a-*/
/* nd clocked out of the device on the falling edge of SCK.All instruction-*/
/* s,addresses and data are transferred with the most significant bit(MSB) */
/* first. */
/* 2005-06-02*/
#define UCHAR unsigned char
#define UINT unsigned int
sbit SPI_CS = P2^2;
sbit SPI_SCK = P2^4;
sbit SPI_SO = P2^6;
sbit SPI_SI = P2^5;
sbit SPI_RESET = P2^3;
sbit SPI_WP = P2^1;
unsigned char SPI_HostReadByte(void){
unsigned char i,rByte=0;
for(i=0;i<8;i++){
SPI_SCK=0;
SPI_SCK=1;
rByte<<=1;
rByte|=SPI_SO;
}
return rByte;
}
void SPI_HostWriteByte(unsigned char wByte){
unsigned char i;
for(i=0;i<8;i++){
if((wByte<<i)&0x80) {SPI_SI=1;}
else {SPI_SI=0;}
SPI_SCK=0;
SPI_SCK=1;
}
}
/*Status Register Format: */
/* ----------------------------------------------------------------------- */
/* | bit7 | bit6 | bit5 | bit4 | bit3 | bit2 | bit1 | bit0 | */
/* |--------|--------|--------|--------|--------|--------|--------|--------| */
/* |RDY/BUSY| COMP | 0 | 1 | 1 | 1 | X | X | */
/* ----------------------------------------------------------------------- */
/* bit7 - 忙标记,0为忙1为不忙。 */
/* 当Status Register的位0移出之后,接下来的时钟脉冲序列将使SPI器件继续*/
/* 将最新的状态字节送出。 */ [Page]
/* bit6 - 标记最近一次Main Memory Page和Buffer的比较结果,0相同,1不同。 */
/* bit5 */
/* bit4 */
/* bit3 */
/* bit2 - 这4位用来标记器件密度,对于AT45DB041B,这4位应该是0111,一共能标记 */
/* 16种不同密度的器件。 */
/* bit1 */
/* bit0 - 这2位暂时无效 */
unsigned char AT45DB041B_StatusRegisterRead(void){
unsigned char i;
SPI_CS=0;
SPI_HostWriteByte(0xd7);
i=SPI_HostReadByte();
SPI_CS=1;
return i;
}
/*描述： */
/* When the last bit in the main memory array has been read,the device will*/
/* continue reading back at the beginning of the first page of memory.As w-*/
/* ith crossing over page boundaries,no delays will be incurred when wrapp-*/
/* ing around from the end of the array to the beginning of the array. */
/*参数： */
/* PA - 页地址,0~2047 */
/* BFA - 指定BUFFER中的起始写入地址 */
/* pHeader - 指定数据的首地址 */
/* len - 指定数据的长度 */
void AT45DB041B_ContinuousArrayRead(UINT PA,UINT BFA,unsigned char *pHeader,UINT len){
unsigned int i;
while(!(AT45DB041B_StatusRegisterRead()&0x80));
// while(i++<255){if(AT45DB041B_StatusRegisterRead()&0x80){break;}}
SPI_CS=0;
SPI_HostWriteByte(0xe8); [Page]
SPI_HostWriteByte((unsigned char)(PA>>7));
SPI_HostWriteByte((unsigned char)((PA<<1)|(BFA>>8)));
SPI_HostWriteByte((unsigned char)BFA);
for(i=0;i<4;i++){SPI_HostWriteByte(0x00);}
for(i=0;i<len;i++){pHeader=SPI_HostReadByte();}
SPI_CS=1;
}
/*描述： */
/* 将指定数据写入从某个地址（0~263）开始的BUFFER中。 */
/*参数： */
/* buffer - 选择BUFFER,01H选择BUFFER 1,02H选择BUFFER 2 */
/* 在该指令序列中,操作码84H选择BUFFER 1,87H选择BUFFER 2 */
/* BFA - BUFFER中的起始地址,0~263 */
/* pHeader - 待存数据的头指针 */
/* len - 待存数据的长度1~264 */
void AT45DB041B_BufferWrite(UCHAR buffer,UINT BFA,UCHAR *pHeader,UINT len){
unsigned int i;
while(!(AT45DB041B_StatusRegisterRead()&0x80));
//while(i++<255){if(AT45DB041B_StatusRegisterRead()&0x80){break;}}
SPI_CS=0;
switch(buffer){
case 1:SPI_HostWriteByte(0x84);break;
case 2:SPI_HostWriteByte(0x87);break;
}
SPI_HostWriteByte(0x00);
SPI_HostWriteByte((unsigned char)(BFA>>8));
SPI_HostWriteByte((unsigned char)BFA);
for(i=0;i<len;i++){SPI_HostWriteByte(pHeader);}
SPI_CS=1;
}
/*描述： */
/* 将指定数据写入从某个地址（0~263）开始的页中：包含2个动作,首先将指定数据*/
/* 写入到BUFFER 1或者BUFFER 2中,其中可以指定BUFFER中的起始写入地址,此写入*/
/* 动作不影响BUFFER中其它地址中的数据,然后再将BUFFER中的整个数据写入到某指*/
/* 定页中(带预擦除)。 */
/*参数： */
/* buffer - 选择BUFFER,01H选择BUFFER 1,02H选择BUFFER 2 */
/* PA - 页地址,0~2047 */
/* BFA - 指定BUFFER中的起始写入地址 */
/* pHeader - 指定数据的首地址 */
/* len - 指定数据的长度 */
void AT45DB041B_BufferToMainMemoryPageProgramWithBuilt_inErase(UCHAR buffer,UINT PA,UINT BFA,UCHAR *pHeader,UINT len){
// unsigned int i;
AT45DB041B_BufferWrite(buffer,BFA,pHeader,len);
while(!(AT45DB041B_StatusRegisterRead()&0x80));
// while(i++<1000){if(AT45DB041B_StatusRegisterRead()&0x80){break;}}
SPI_CS=0;
switch(buffer){
case 1:SPI_HostWriteByte(0x83);break;
case 2:SPI_HostWriteByte(0x86);break;
}
SPI_HostWriteByte((unsigned char)(PA>>7));
SPI_HostWriteByte((unsigned char)(PA<<1));
SPI_HostWriteByte(0x00);
SPI_CS=1;
}
/*描述： */
/* 与上一个函数的唯一区别是不带预擦除。 */
void AT45DB041B_BufferToMainMemoryPageProgramWithoutBuilt_inErase(UCHAR buffer,UINT PA,UINT BFA,UCHAR *pHeader,UINT len){
unsigned int i=0;
AT45DB041B_BufferWrite(buffer,BFA,pHeader,len);
while(!(AT45DB041B_StatusRegisterRead()&0x80));
// while(i++<1000){if(AT45DB041B_StatusRegisterRead()&0x80){break;}}
SPI_CS=0;
SPI_HostWriteByte(0x87+buffer);
SPI_HostWriteByte((unsigned char)(PA>>7));
SPI_HostWriteByte((unsigned char)(PA<<1));
SPI_HostWriteByte(0x00);
// for(i=0;i<len;i++){SPI_HostWriteByte(pHeader);}
SPI_CS=1;
}
void main(void){
unsigned char i;
UCHAR data test[32];
// SPI_RESET = 0;
// SPI_WP = 0;
// delay(2000);
// SPI_RESET = 1;//
// SPI_WP = 1;//取消写保护
i=AT45DB041B_StatusRegisterRead();
for(i = 0; i < 32; i++)
{test = i + 0x20;}
AT45DB041B_BufferToMainMemoryPageProgramWithBuilt_inErase(1,0,0,test,32);
memset(test,0x26,32);
AT45DB041B_ContinuousArrayRead(0,0,test,32);
for(i = 0; i < 32; i++)
{test = i + 0x10;}
AT45DB041B_BufferToMainMemoryPageProgramWithoutBuilt_inErase(2,1,0,test,32);
memset(test,0x55,32);
AT45DB041B_ContinuousArrayRead(1,0,test,32);
while(1){}
}
| | | 更新时间：2007-6-1 11:19:09 |  |
|
|
|
|
|
|
