/* demo 4 : INT_CHAN_3, timer interrupt, demo		       */
/*	    (it is designed to be a machine independent timer) */
/* step 1 : run demo4.exe				       */
/* ----------------------------------------------------------- */

#include "PIO.H"

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

WORD init_high();
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();
static int COUNT,now_int_state,irqmask;

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_high();	/* interrupt initialize, INIT_CHAN_3 is HIGH now   */
COUNT=0;
printf("\n*** show the count of Low_pulse ***\n");

for (;;)
    {
    printf("\nLow Pulse Count=%d (one low pulse every second) INT_STATUS=[%x %x]",COUNT,
	      inportb(wBase+7)&8, now_int_state);
    if (kbhit()!=0) {getch(); break;}
    }

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

/* -------------------------------------------------------------------- */
/* Use INT_CHAN_3 as external interrupt signal				*/

WORD init_high()
{
DWORD dwVal;

disable();

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

/* select CLK1=32768 Hz 					*/
outportb(wBase+0xf0,0x15);  /* CTRL_D0=1-->timer clock=32768 Hz */

/* program OUT1 to 2 Hz 					*/
pio_d48_c1(0x76,0,0x40);   /* COUNTER1,MODE-3,32768/0x4000=2 Hz */

/* program OUT2 to 1 Hz 					*/
/* note: the 8254 need extra 2-clock for initialization 	*/
pio_d48_c2(0xb6,2,0);	   /* COUNTER2,MODE-3,2/2=1Hz		*/

for (;;)		   /* wait COUT2=HIGH			*/
    {
    if ((inportb(wBase+7)&8)!=0) break;
    }

/* Note: now the COUT2 is HIGH					*/
/*	 --> INV3 must select the inverted COUT2		*/
/*	 --> INT_CHAN_3=!COUT2=init_LOW, active_HIGH		*/

outportb(wBase+0x2a,0);    /* select the inverted COUT2 	*/
			   /* INT_CHAN_3=!COUT2 		*/
now_int_state=1;	   /* now COUT2 is high 		*/
outportb(wBase+5,8);	   /* enable INT_CHAN_3 interrupt	*/
enable();
}

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

void interrupt irq_service()
{
if (now_int_state==1)		/* now COUT2 is changed to LOW	      */
   {				/* --> INT_CHAN_3=!COUT2=HIGH now     */
   COUNT++;			/* find a LOW_pulse (COUT2)	      */
   if((inportb(wBase+7)&8)==0)	/* the COUT2 is still fixed in LOW    */
     {				/* --> need to generate a high_pulse  */
     outportb(wBase+0x2a,8);	/* INV3 select the non-inverted input */
				/* INT_CHAN_3=COUT2=LOW -->	      */
				/* INT_CHAN_3 generate a high_pulse   */
     now_int_state=0;		/* now COUT2=LOW		      */
     }
   else now_int_state=1;	/* now COUT2=HIGH		      */
				/* (no need to generate high_pulse )  */
   }
else				/* now COUT2 is changed to HIGH       */
   {				/* --> INT_CHAN_3=COUT2=HIGH now      */
				/* find a HIGH_pulse (COUT2)	      */
   if((inportb(wBase+7)&8)==8)	/* the COUT2 is still fixed in HIGH   */
     {				/* --> need to generate a high_pulse  */
     outportb(wBase+0x2a,0);	/* INV3 select the inverted input     */
				/* INT_CHAN_3=!COUT2=LOW -->	      */
				/* INT_CHAN_3 generate a high_pulse   */
     now_int_state=1;		/* now COUT2=HIGH		      */
     }
   else now_int_state=0;	/* now COUT2=LOW		      */
				/* (no need to generate high_pulse )  */
   }

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);
}