Newbie here,Help on Accessing bits and nibbles of a Byte

crukid88 · Joined: 04 Oct 2007 Posts: 14

Does anyone know how to access nibbles and bits of a byte. Also same with the Word,how to access it by byte. Help really needed hope you could advice.

SherpaDoug · Joined: 07 Sep 2003 Posts: 1640 Location: Cape Cod Mass USA

Look in the CCS manual at the bit_clear(), bit_set(), and bit_test() functions, also look at the shift, rotate, and swap functions. It wouldn't hurt to read the manual cover to cover.

The "old school" way to set a bit is to logically AND the byte with a "mask" byte which has the required bit set. You clear a bit by ORing with a mask with all bits 1 except the specified bit. You test a bit by ANDing and then checking for zero.
_________________
The search for better is endless. Instead simply find very good and get the job done.

crukid88 · Joined: 04 Oct 2007 Posts: 14

so theres no way of directly accessing it?like for example bits in an interrupt register or the TRISB where we set it like let say TRISB.F1 etc...?

TobyHarris · Joined: 27 Sep 2007 Posts: 5

Also look at make8 for splitting a word or long word up into its constituent bytes.

rnielsen · Joined: 23 Sep 2003 Posts: 852 Location: Utah

There are ways to access the different registers, directly.

First you need to define the address of the register and give it a name:

crukid88 · Joined: 04 Oct 2007 Posts: 14

This is really a big help to me as a beginner thanks