While trying to interface flash SST25VF512 with AT80c51, i find difficulty in Byte program mode of writing to flash.
This is the code i used, could somebody who has worked on this please help me out,
void main(void){ ce = 1; SCK = 0; TMOD = 0x20; TH1 = -3; // 9600 baud SCON = 0x50; TR1 = 1; TI = 1; addr = 0x00000012; Rd_ID = Read_ID(); Byte_Program(addr); void Byte_Program(unsigned long addr){ ce = 0; E_WRSR(); WREN(); Send_Byte(0x02); // Byte Program CMD Send_Byte(((addr & 0xFFFFFF) >> 16)); // sending 3 address bytes Send_Byte(((addr & 0xFFFF) >> 8)); Send_Byte(addr & 0xFF); Send_Byte(0x10); //send data SR_byte = Read_Status_Register(); while((SR_byte &0x01) != 0x00){ SR_byte = Read_Status_Register(); } ce = 1; } void E_WRSR(){ ce = 0; Send_Byte(0x50); // enable Status Reg ce = 1; ce = 0; Send_Byte(0x01); // select write to status register Send_Byte(0x00); // mode 0, ce = 1; } void WREN(){ ce = 0; Send_Byte(0x06);// to Write enable ce = 1; } unsigned char Get_Byte(){ unsigned char i=0, in=0, temp=0; for(i=0;i<8;i++){ in = (in << 1); temp = SO; SCK = 1; if (temp == 1){ in = in | 0x01; } SCK = 0; } return in; } void Send_Byte(unsigned char b_out){ for(i=0;i<8;i++){ if((b_out & 0x80) == 0x80) si = 1; else si = 0; SCK = 1; b_out = (b_out << 1); SCK = 0; } }
Thanks in advance,
Thanks Dave, so you suggest WRSR need not be written IN the write operation is it, fine, then how do we set the memory protection bits? Without setting them, is there any way to write,
"After the rated number of cycles on your flash chip, the status register will burn out and the chip will stop working, even if the data sectors are still good." Could you please tell this rated number of cycles. Can write operation process be completed within that?
"Using WRSR is not necessary, and will limit the lifetime of the chip if you frequently write data." Is it apart from the 10,000 cycles for the chip as a whole?
Then how do we get to write data and check also that the program is running fine,