Kevin, I'm not sure if you're clear on the use of SCLK - effectively the SCLK is like cranking the handle to send/receive a bit at a time - the speed of the SCLK is not critical (there are upper limits though) to the MAX186. This is unlike asynchronous serial that has fixed timing.

Following is some 'c' code I wrote many years ago that uses the max186 and bit bangs the SPI. Pretty much your assembler code would follow the same structure. Hopefully this helps.


[PRE]
int GetAdc(char input) /* returns value of adc input sampled 8 times */
{
register char a , b , cmd186 , e;
register unsigned int c,d;

switch(input) /* max186 has funny input bit addressing */
{
case 0:
cmd186=0x8f;
break;
case 1:
cmd186=0xcf;
break;
case 2:
cmd186=0x9f;
break;
case 3:
cmd186=0xdf;
break;
case 4:
cmd186=0xaf;
break;
case 5:
cmd186=0xef;
break;
case 6:
cmd186=0xbf;
break;
case 7:
cmd186=0xff;
break;
default:
cmd186=0; /* has the command & input# for the max186 */
}
d=0; /* zero the accumulator */
e=0;
while (e < 8)
{
ADC_CS=0; /* select the max186 */
b=cmd186; /* copy cmd so we can shift it .. */
for (a=0;a<8;a++) /* shift the cmd out to max186 */
{
if ((b & 0x80) !=0 ) DIN=1;
else DIN=0;
b=b<<1;
SCLK=1;
SCLK=0;
}
for (a=0;a < 40;a++); /* wait at least 10 uS for conversion */
c=0;
for (a=0;a<12;a++) /* grab the 12 bit result from the max186 */
{
c=c<<1; /* pre shift */
SCLK=1;
SCLK=0; /* clock the next data bit */
if (DOUT == 1) c|=0x0001; /* into the var */
}
ADC_CS=1;
d+=c; /* accumulate the samples */
e++; /* next sample */
}
return(d);
}

[/PRE]