The Following is a sample ‘C’ that reads a character from the USB and writes it back out.

#include <c:\sxc\include\dev\SX28AC.H>

#include <c:\sxc\include\port.h>

#define TXEn

PORTA.3

// INPUT

#define WRITE

PORTA.2

// OUTPUT

#define READn

PORTA.1

// OUTPUT

#define RXFn

PORTA.0

// INPUT

#pragma FUSE = FOSC_HS2 & TURBO & WDTD

#pragma FUSEX = EXTEND

unsigned char byte;

/*--------------------------------------------------------------------------*/

/*

*/

/*--------------------------------------------------------------------------*/

void send_byte()

{

DDR(PORTC,0x00);

// make PORTC output

WRITE=1;

NOP();

PORTC=byte;

NOP();

WRITE=0;

DDR(PORTC,0xFF);

// now make PORTC input

}

/*--------------------------------------------------------------------------*/

/*

*/

/*--------------------------------------------------------------------------*/

void read_byte()

{

READn=0;

NOP();

byte=PORTC;

NOP();

READn=1;

}

/*--------------------------------------------------------------------------*/

/*

*/

/*--------------------------------------------------------------------------*/

void main()

{

OPTION(RTW|RTE_D|PSA);

// start with RTC int disabled

DDR(PORTC,0xFF);

// USB Data Port

DDR(PORTB,0xFF);

// all inputs

DDR(PORTA,0xF9);

// USB Status lines

WRITE=0;

// Initialize control

READn=1;

// Outputs Here

while (1)

// Loop forever

{if (RXFn == 0)

// Is there a character available

{read_byte(); // Yes, so get it

send_byte(); // and send it back out

}

}

}

Setup and running.

Place the USB device in an empty breadboard, noting proper pin orientation. If you are using

the USB adapter cable, while it is NOT plugged into a master or PC, plug the proper end into the

breadboard next to the USB245 so that the pin with the Red wire connects to USB245 pin 22, and

the pin with the black wire connects to pin 19. Place a jumper wire between pins 22 & 23 of the

USB245 on the breadboard. At this point only the top-right 6 pins of the USB245 will be attached.

With nothing else attached to the module, except as noted above, now plug the other end of the

cable into the PC. It should recognize a new USB device a start searching for drivers. When it