Cypress Semiconductor CY8C21534 Dokumentacja Pobierz pdf (Strona 56)

Appendix 2

6(15)

while(UART_cReadChar() == 0x00); // Scans for valid data

data_size[0] = UART_bReadRxData(); // Stores Lowest byte of

// file size

data_size[1] = UART_cGetChar(); // Stores middle byte of file size

data_size[2] = UART_cGetChar(); // Stores highest byte of file size

// Find number of bytes left after all 512 size writes will be made

file_size_partial = ((data_size[1]<<8)|data_size[0]) + 1;

while(file_size_partial > 512) file_size_partial = file_size_partial - 512;

file_size = file_size_partial;

// Writes file size to directory entry string

directory[60] = data_size[0];

directory[61] = data_size[1];

directory[62] = data_size[2];

// Gets number of sectors for proper future loop counts

while(UART_cReadChar() == 0x00);

number_of_sectors[0] = UART_bReadRxData();

number_of_sectors[1] = UART_cGetChar();

sectors = ((number_of_sectors[1]<<8)|number_of_sectors[0]) - 1;

card_initialize(); // SD card initialization into SPI mode

Counter8_WritePeriod(0x30); // Sets period to 30 clocks

Counter8_WriteCompareValue(0x15); // Generates a 50% duty cycle

write_data_init(0x00, 0x00, 0x04, 0x00); // Writes first FAT entry

start_token();

for(i=0;i<sizeof(fat);i++)

{

write_data_raw(fat[i])

;

}

write_data_fill(sizeof(fat));

write_CRC();

stop_token();

// Address sector 2, offset 400

write_data_init(0x00, 0x01, 0xE2, 0x00); // Writes second FAT entry

start_token();

for(i=0;i<sizeof(fat);i++)

{

write_data_raw(fat[i])

;

}

write_data_fill(sizeof(fat));

write_CRC();

stop_token();

// Address sector 241, offset 1E200

write_data_init(0x00, 0x03, 0xC0, 0x00); // Writes DIRECTORY entry

start_token(); // Address sector 480, offset 3C000

for(i=0;i<sizeof(directory);i++)

{

write_data_raw(directory[i]);

}

write_data_fill(sizeof(directory));

write_CRC();

stop_token();

1 2 ... 51 52 53 54 55 56 57 58 59 60 61 ... 68 69

Komentarze do niniejszej Instrukcji

Brak uwag

Cypress Semiconductor CY8C21534 Dokumentacja Strona 56

Komentarze do niniejszej Instrukcji