Texas Instruments MSC1210 - Manual (Page 252)

Summation/Shifter
17-24
while(!(AISTAT & 0x20));
j = ADRESL;
for (i = 0; i < 20; i++)
{ // dump 20 conversions
/*wait for DRBY bit*/
while(!(AISTAT & 0x20));
}
/*set up Summation / Shifter*/
/*Select Summation / Shifter option,
Acc Count = 8, Shift Count = 8
*/
init_accumulator ();
//extract Accumulate−Count from SSCON SFR Register.
j = SSCON & 0x38;
j /= 8;
j = 1 << (j + 1);
return (j);
}
void a_to_d_accumulate (void) interrupt 6 using 1
{
/*interrupt type 6 vectored to 0x33.
Any AI type interrupt would come to this ISR.
Evaluating the SUM and ADC bits of AISTAT will determine
whether the ISR call was due to the A/D Converter interrupt or
the Summation/Shifter interrupt*/
if (AISTAT & 0x20)
{//A/D conversion interrupt
converting = 0;
AISTAT &= ~0x20; /*clear ADC bit*/
}
if (AISTAT & 0x40)
{//Accululator/Shifter interrupt
averaging = 0;
AISTAT &= ~0x40; /*clear SUM bit*/
}
return;
}
void main(void)
{
int i;