/*************************
*
*  test program to verify timing interferences
*  between concurrent routines
*  coexistence of short and frequent with long and non-preemptive ones
*
*    STR Lab
*    Luis Almeida, 2003/09/29
*
* Changelog
* -2006/09/17, PP
*    Update on port address (from ox2100 to 0xFD00) due to kit firmware update
*
*****************************/

#include <dos.h>
#include "det188.h"
#pragma inline

#define tmr2_cntl_value 0xe001    /* timer 2 enabled, generate int, run cont */
#define tmr2_maxc_value  1250    /* clock counts per ms */
				/* remember that CPU internal clock = 5MHz */

#define tmr_cntl_value  0  /* unmasked, highest priority=0 */
#define mask_value      0x00fd  /* all ints masked */

/* [PP] Note: due to firmware update in 2004, port address changed from 0x2100 to 0xfd00 */
/*      Default PBA=0xFC00, chip select from PCS2 */
#define p_port_add 0xfd00  /* address of parallel port in the I/O card */


void interrupt t2_isr(void);
void heavy_load(void);

unsigned int count;

void main(void)
{
unsigned long far *int_vect_pointer;
int i;
unsigned char TIME_SLICE, leds, leds_done, nsec;

/* force interrupts off */
disable();

count=0;

/* timer2 count (ms) */
TIME_SLICE=1;

/* set timer2 interrupt vector (at 4*tmr2_int_numb) to tick_handler */
int_vect_pointer=(unsigned long far*)MK_FP(0,4*tmr2_int_numb);
*(int_vect_pointer)=(unsigned long)t2_isr;

/*** program timer2 to generate ints at apropriate rate (TIME_SLICE ms) ***/
outport(tmr2_cntl_reg,tmr2_cntl_value);
outport(tmr2_maxc_reg,tmr2_maxc_value*TIME_SLICE);

/**** program PIC ****/
/* all ints masked */
outport(mask_reg,mask_value);
/* unmask timer, priority=0 highest */
outport(tmr_cntl_reg,tmr_cntl_value);

leds=0xaa;
outportb(p_port_add,leds);
for(i=0;i<10000;i++);
leds^=0xff;
outportb(p_port_add,leds);
for(i=0;i<10000;i++);
leds^=0xff;
outportb(p_port_add,leds);
for(i=0;i<10000;i++);
leds^=0xff;
outportb(p_port_add,leds);
leds_done=0;


/* interrupts on */
enable();

while(1)
/*	{
	while(count<256);
	leds^=0xff;
	outportb(p_port_add,leds);
	count=0;
	}
*/
	{
	/* every 128ms, toggle leds */
	nsec=(unsigned char) (count/128);
	if(count==(unsigned int)(nsec*128))
		{
		if (leds_done==0)
			{
			leds^=0xff;
			outportb(p_port_add,leds);
			leds_done=1;
			}
		}
	else
		/* allow following toggles */
		leds_done=0;

	/* every 5s */
	if(count>5000)
		{
		/* reset counter and invoke heavy non-preemptive load (ints disabled) */
		count=0;
		/*heavy_load();*/
		}
	}
}


void interrupt t2_isr()
{
count++;
outport(eoi_reg,timers_eoi);
}

void heavy_load()
{
unsigned int i,j;
disable();
for(i=0;i<32000;i++)
	for(j=0;j<10;j++);
enable();
}