It depends on how much you are draining/sourcing through the pins.

If you want to be sure, you need to use shadow registers instead of directly
reading the hardware.

UINT8     shadowB;

shadowB = (shadowB & 0x0F) | (NEWVALUE & 0xF0);   // Updates high nybble
PORTB = shadowB;    // Send updated shadow to hardware

Andy










WF <wf@BLUSOFT.ORG.BR> on 06/13/2000 03:42:33 PM

Please respond to pic microcontroller discussion list <PICLIST@MITVMA.MIT.EDU>








 To:      PICLIST@MITVMA.MIT.EDU

 cc:      (bcc: Andrew Kunz/TDI_NOTES)



 Subject: Re: [OT]: CCS C COMPILER








My question is:

Will affect the remainder bits? The remainders bits are configurated as
INPUT and OUTPUT...

Miguel
----- Original Message -----
From: Andrew Kunz <akunz@TDIPOWER.COM>
To: <PICLIST@MITVMA.MIT.EDU>
Sent: Tuesday, June 13, 2000 4:42 PM
Subject: Re: [OT]: CCS C COMPILER


> PORTB = (PORTB & 0x0F) | (NEWVALUE & 0xF0);   // Updates high nybble
>
> PORTB = (PORTB & 0xF0) | (NEWVALUE & 0x0F);   // Updates low nybble
>
> Andy