Kontron pITX-SP - Manual (Page 24)

KTD-S0003-C Page 20 CPLD Interface
p ITX-SP Software Guide
6.2.2 Digital I/O Example
BIOS Setup settings (entry Advanced/Onboard Device Configuration/GPIO Configuration):
GPIO Pin 0 - 3 Input
GPIO Pin 4 - 7 Output
Default Output State Low
#include <stdio.h>
#include <dos.h>
#include <conio.h>
#define CPLD_BASE_ADDR 0xA80
#define GPIO_INPUT_INDEX 0xA0
#define GPIO_OUTPUT_INDEX 0xA1
#define GPIO_INPUT_MASK 0x0F
void WriteDigitalIO (unsigned char value)
{
outp (CPLD_BASE_ADDR, GPIO_OUTPUT_INDEX);
outp (CPLD_BASE_ADDR+1, value);
}
unsigned char ReadDigitalIO (void)
{
unsigned
char value;
outp (CPLD_BASE_ADDR, GPIO_INPUT_INDEX);
value = inp (CPLD_BASE_ADDR+1);
return value;
}
void main (void)
{
unsigned
char val;
WriteDigitalIO (0x50);
getch ();
WriteDigitalIO (0xA0);
getch ();
val = ReadDigitalIO () & GPIO_INPUT_MASK;
printf ("\nInput value = %02X\n", val);
}