Connect Flash Card with PIC18F4520

• CF_Data_Port : Compact Flash data port
• CF_RDY : Ready signal line
• CF_WE : Write enable signal line
• CF_OE : Output enable signal line
• CF_CD1 : Chip detect signal line
• CF_CE1 : Enable signal line
• CF_A2 : Address pin 2
• CF_A1 : Address pin 1
• CF_A0 : Address pin 0
• CF_RDY_direction : Direction of the Ready pin
• CF_WE_direction : Direction of the Write enable pin
• CF_OE_direction : Direction of the Output enable pin
• CF_CD1_direction : Direction of the Chip detect pin
• CF_CE1_direction : Direction of the Chip enable pin
• CF_A2_direction : Direction of the Address 2 pin
• CF_A1_direction : Direction of the Address 1 pin
• CF_A0_direction : Direction of the Address 0 pin

must be defined before using this function.

// set compact flash pinout
char Cf_Data_Port at PORTD;

sbit CF_RDY at RB7_bit;
sbit CF_WE  at LATB6_bit;  // for writing to 
output pin always use latch (PIC18 family)
sbit CF_OE  at LATB5_bit;  // for writing 
to output pin always use latch (PIC18 family)
sbit CF_CD1 at RB4_bit;
sbit CF_CE1 at LATB3_bit;  // for writing to
 output pin always use latch (PIC18 family)
sbit CF_A2  at LATB2_bit;  // for writing to
 output pin always use latch (PIC18 family)
sbit CF_A1  at LATB1_bit;  // for writing to
 output pin always use latch (PIC18 family)
sbit CF_A0  at LATB0_bit;  // for writing to
 output pin always use latch (PIC18 family)

sbit CF_RDY_direction at TRISB7_bit;
sbit CF_WE_direction  at TRISB6_bit;
sbit CF_OE_direction  at TRISB5_bit;
sbit CF_CD1_direction at TRISB4_bit;
sbit CF_CE1_direction at TRISB3_bit;
sbit CF_A2_direction  at TRISB2_bit;
sbit CF_A1_direction  at TRISB1_bit;
sbit CF_A0_direction  at TRISB0_bit;
// end of cf pinout
...
Cf_Init();      // initialize CF 

• 1 – if CF card was detected
• 0 – otherwise

// Wait until CF card is inserted:
do
  asm nop;
while (!Cf_Detect());

// enable compact flash
Cf_Enable();

// disable compact flash
Cf_Disable();

• address: the first sector to be prepared for reading operation.
• sector_count: number of sectors to be prepared for reading operation.

// initialize compact flash for reading from sector 590
Cf_Read_Init(590, 1);

// Read a byte from compact flash:
char data;
...
data = Cf_Read_Byte();

• address: the first sector to be prepared for writing operation.
• sectcnt: number of sectors to be prepared for writing operation.

// initialize compact flash for writing to sector 590
Cf_Write_Init(590, 1);

• data_: byte to be written.

char data_ = 0xAA;
...
Cf_Write_Byte(data_);

• sector_number: sector to be read.
• buffer: data buffer of at least 512 bytes in length.

// read sector 22
unsigned short data[512];
...
Cf_Read_Sector(22, data);

• sector_number: sector to be written to.
• buffer: data buffer of 512 bytes in length.

// write to sector 22
unsigned short data[512];
...
Cf_Write_Sector(22, data);

• 0 – if CF card was detected and successfully initialized
• 1 – if FAT16 boot sector was not found
• 255 – if card was not detected

 // Init the FAT library
if (!Cf_Fat_Init()) {    // Init the FAT library
...
}