Multiplexer channel selection

[Castor]

... but as the PIC will perform the A/D conversion ... a Porta Analog input has some good chance to be in use ... if you do not use another ADC input ( PortE 0,1 or 2 for a 16F877a )

Hey, thanks for the great answer.
It works like a charm. In fact I use a 16 bit external A/D converter so using PORTA pins as digital I/O doesn't pose an issue. What if the selection pins are scattered across two ports ? Can I get around that without selecting each and every output manually ? Or reworking the board ? (I didn't quite think about channel selection when I built it)

'DCD
'----------
'RE2 G1,G2
'RB7 A
'RB6 B
'RB5 C
'RC6 D

[Acetronics2]

What if the selection pins are scattered across two ports ?

Why not ...

you'll have to write two lines for Ports masking instead of one !

Can I get around that without selecting each and every output manually ? Or reworking the board ?

if you have a pot or button available and a free Pic input or two ... you can easily make the manual channel selection "by soft" ...

(I didn't quite think about channel selection when I built it)

but , may be, you'll have to add a small board on the existing one ( in french : une impériale !!! )

Alain