Interfacing PIC Microcontrollers

5

Data Processing

Most microcontroller programs need to process data using arithmetic or logi-

cal operations. The main types of data in general processor systems are num-

bers and characters. Characters are not too much of a problem as there are only

26 letters in the alphabet and 10 numerical characters. Even allowing for upper

and lower case, that is only 62 codes are required. The basic ASCII character

set thus only requires a 7-bit code, which also provides for most other key-

board symbols (see previous chapter for table of ASCII codes). Use of the

eighth bit allows special character sets to be added.

Numerical data is a bit more of a problem, ...