I'm having trouble getting an analog reading on GP4/AN3 of the 12F615 chip. Been wading through the spec sheet and trying to find all the right bits in the various registers. No matter what I try, I get a value of 1023 from this:
adcin gpio.4,reading

Here are the register setups I'm using:
ADCON0 = %11001101 ' select analog input for AN3
ANSEL = %00001000 ' select analog input for AN3
vrcon = %10000000 ' CVref = ON
CMCON0 = %10000111 ' comparators off

Can anyone tell me what I'm doing wrong? Must be something really dumb.