Omega OME-PIO-D144 - Manual (Page 42)

outp(wBase+5,0); /* disable all interrupt */
PIO_DriverClose();
}
/* --------------------------------------------------------------- */
/* Use PC0 as external interrupt signal */
WORD init_low()
{
DWORD dwVal;
disable();
outp(wBase+5,0); /* disable all interrupt */
if (wIrq<8)
{
irqmask=inp(A1_8259+1);
outp(A1_8259+1,irqmask & (0xff ^ (1 << wIrq)));
setvect(wIrq+8, irq_service);
}
else
{
irqmask=inp(A1_8259+1);
outp(A1_8259+1,irqmask & 0xfb); /* IRQ2 */
outp(A1_8259+1,irqmask & (0xff ^ (1 << wIrq)));
irqmask=inp(A2_8259+1);
outp(A2_8259+1,irqmask & (0xff ^ (1 << (wIrq-8))));
setvect(wIrq-8+0x70, irq_service);
}
outp(wBase+0x2a,0); /* select the non-inverte input */
now_int_state=0; /* now int_signal is low */
outp(wBase+5,1); /* enable interrupt */
enable();
}
void interrupt irq_service()
{
if (now_int_state==0)
{
COUNT++; /* find a high_pulse */
outp(wBase+0x2a,1); /* select the inverte input */
now_int_state=1; /* now int_signal is High */
}
else
{
/* find a low_pulse here */
outp(wBase+0x2a,0); /* select the non-inverte input */
now_int_state=0; /* now int_signal is High */
}
if (wIrq>=8) outp(A2_8259,0x20);
outp(A1_8259,0x20);
}
Refer to Sec. 2.5.1 for more information.
OME-PIO-D144 User’s Manual (Ver.2.1, Sep/2001) ---- 40