/* demo 7 : INT_CHAN_2, 16-bit down-counter (using interrupt)	   */
/* step 1 : apply a init_HIGH & active_LOW signal to PC0 of port-2 */
/* step 2 : run demo7.exe					   */
/* --------------------------------------------------------------- */

#include "PIO.H"

#define A1_8259 0x20
#define A2_8259 0xA0
#define EOI	0x20

WORD init_low();
WORD wBase,wIrq;

WORD pio_d48_c0(char cConfig, char cLow, char cHigh);
WORD pio_d48_c1(char cConfig, char cLow, char cHigh);
WORD pio_d48_c2(char cConfig, char cLow, char cHigh);

static void interrupt irq_service();
int COUNT,irqmask,now_int_state;

int main()
{
int  i,j;
WORD wBoards,wRetVal;
WORD wSubVendor,wSubDevice,wSubAux,wSlotBus,wSlotDevice,t1,t2,t3,t4,t5;
char c;
DWORD dwVal;

/* step 1: find address-mapping of PIO/PISO cards */
clrscr();
wRetVal=PIO_DriverInit(&wBoards,0x80,0x01,0x30);  /* for PIO-D48 */
printf("\nThrer are %d PIO_D48 Cards in this PC",wBoards);
if (wBoards==0) exit(0);

printf("\n----------------- The Configuration Space -------------------------");
for(i=0; i<wBoards; i++)
   {
   PIO_GetConfigAddressSpace(i,&wBase,&wIrq,&wSubVendor,&wSubDevice,&wSubAux,
			     &wSlotBus,&wSlotDevice);
   printf("\nCard_%d: wBase=%x,wIrq=%x,subID=[%x,%x,%x],SlotID=[%x,%x]"
	  ,i,wBase,wIrq,wSubVendor,wSubDevice,wSubAux,wSlotBus,wSlotDevice);
   printf(" --> ");
   ShowPioPiso(wSubVendor,wSubDevice,wSubAux);
   }

/* select card_0 */
PIO_GetConfigAddressSpace(0,&wBase,&wIrq,&t1,&t2,&t3,&t4,&t5);

/* step 2: enable all D/I/O port				   */
outportb(wBase,1);	    /* enable D/I/O			   */

init_low(); /* interrupt initialize, INT_CHAN_2 now is initial LOW */
COUNT=0;
printf("\n*** show the count of Low_pulse **\n");

for (;;)
    {
    printf("\nInterrupt Count=%d (one interrupt=5 low_pulse)",COUNT);
    if (kbhit()!=0) {getch(); break;}
    }

outportb(wBase+5,0);		/* disable all interrupt */
PIO_DriverClose();
}

/* -------------------------------------------------------------------- */
/* Use INT_CHAN_2 as external interrupt signal				*/

WORD init_low()
{
DWORD dwVal;

disable();

if (wIrq<8)
   {
   irqmask=inportb(A1_8259+1);
   outportb(A1_8259+1,irqmask & (0xff ^ (1 << wIrq)));
   setvect(wIrq+8, irq_service);
   }
else
   {
   irqmask=inportb(A1_8259+1);
   outportb(A1_8259+1,irqmask & 0xfb);			   /* IRQ2 */
   outportb(A1_8259+1,irqmask & (0xff ^ (1 << wIrq)));
   irqmask=inportb(A2_8259+1);
   outportb(A2_8259+1,irqmask & (0xff ^ (1 << (wIrq-8))));
   setvect(wIrq-8+0x70, irq_service);
   }

outportb(wBase+5,0);		/* disable all interrupt */

/* select PC0 of port_2 as init_HIGH & active_LOW sinal 		 */
outportb(wBase+0xf0,0);     /* CTRL_D1=0 -> init_HIGH, active_LOW	 */

/* NOTE : The 8254 need the extra starting two event_clock to initialize */
/*	  So the counter value before the starting two clock is error	 */
pio_d48_c0(0x30,3,0);		/* COUNTER0,mode-0 down count 3+2=5	 */

/* Note: now the COUT0 is LOW					*/
/*	 --> INV2 must select the non-inverted COUT0		*/
/*	 --> INT_CHAN_2=COUT0=init_LOW, active_HIGH		*/

outportb(wBase+0x2a,4);    /* select the non-inverted COUT0	*/
			   /* INT_CHAN_2=COUT0=LOW now		*/
now_int_state=0;	   /* now COUT0 is LOW			*/
outportb(wBase+5,4);	   /* enable INT_CHAN_2 interrupt	*/

for (;;)		   /* wait COUT0=LOW			*/
    {
    if ((inportb(wBase+7)&4)==0) break;
    }
enable();
}

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

void interrupt irq_service()
{
if (now_int_state==0)		/* now COUT0 is changed to HIGH       */
   {				/* --> INT_CHAN_2=COUT0=HIGH now      */
   COUNT++;			/* find a HIGH_pulse (COUT0)	      */
   pio_d48_c0(0x30,3,0);	/* COUNTER0,mode-0 down count 3+2=5   */
				/* now INT_CHAN_2=COUT0=LOW now -->   */
				/* INT_CHAN_2 generate a HIGH_pulse   */
   now_int_state=0;		/* now COUT0=LOW		      */
   }

if (wIrq>=8) outportb(A2_8259,0x20);
outportb(A1_8259,0x20);
}

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

WORD pio_d48_c0(char cConfig, char cLow, char cHigh)	/* COUNTER_0 */
{
outportb(wBase+0xec,cConfig);
outportb(wBase+0xe0,cLow);
outportb(wBase+0xe0,cHigh);
return(NoError);
}

WORD pio_d48_c1(char cConfig, char cLow, char cHigh)	/* COUNTER_1 */
{
outportb(wBase+0xec,cConfig);
outportb(wBase+0xe4,cLow);
outportb(wBase+0xe4,cHigh);
return(NoError);
}

WORD pio_d48_c2(char cConfig, char cLow, char cHigh)	/* COUNTER_2 */
{
outportb(wBase+0xec,cConfig);
outportb(wBase+0xe8,cLow);
outportb(wBase+0xe8,cHigh);
return(NoError);
}