I have finally enrolled in a continuing education class on midrange PICs. 
We are concentrating on the 16F877A using a QL200 development board to test 
our programs.

I'm having a bit of a brain fart here in comprehending how ADCON1 is 
configured.  I find plenty of references online as well as my study 
materials that state setting ADCON1 to 0x06 sets all PORTA (and E since I 
see they have the same address) pins as digital I/O vice analog.

I'm trying to see how or why this happens.  How does setting bits 1 and 2 
(0x06) high change the I/O to digital?

I'm looking at Table 4-2 (page 43) in the 16F877A datasheet. I am apparently 
missing something in understing WHY 0x06 is used, and what I would choose if 
I wanted an analog I/O.  What configuration chart am I overlooking that 
describes the settings?

This is a portion of my code: (I apologize ahead of time for any formatting 
issues.)

start   bsf    STATUS,RP0                 ;Switch to Bank1 for ADCON1
          bcf   STATUS,RP1                 ;Make sure in Bank1
          movlw 0x06                             ;Load value to make ports A 
& E digital I/O
          movwf ADCON1                    ;as opposed to Analog inputs

Thanks for any clarification anyone can offer.

Joe

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