PIC Microcontoller Program Flow ASCII Conversion Method

Convert ASCII to Upper Case

From http://www.myke.com/basic.htm

This is a practical application of conditional replacement. I think this subroutine demonstrates how the code works quite well.

ToUpper:
 addlw 255 - 'z' ; Get the High limit
 addlw 'z' - 'a' + 1 ; Add Lower Limit to Set Carry
 btfss STATUS, C ; If Carry Set, then Lower Case
 addlw h'20' ; Carry NOT Set, Restore Character
 addlw 'A' ; Add 'A' to restore the Character
 return

See:

• /techref/microchip/math/radix/b2a-7b3d-ba.htm Binary 7bit to ASCII decimal 3 digits by Bob Axtell James Newton replies: The table method shown in that code could be used to convert aSCII to upper case in fewer cycles, but it would be a much larger program.+

  +

.