CCS PCM Output 003 - Multiply by a power of 2
From Pigmeo Development Wiki
C language
#include <16F716.h> #byte PORTA=0x05 #byte PORTB=0x06 #byte Result=0x20 void main() { Result=PORTA*4; }
Assembly language
0000: MOVLW 00 0001: MOVWF 0A 0002: GOTO 004 0003: NOP .................... #include <16F716.h> .................... //////// Standard Header file for the PIC16F716 device //////////////// .................... #device PIC16F716 .................... #list .................... .................... .................... #byte PORTA=0x05 .................... #byte PORTB=0x06 .................... #byte Result=0x20 .................... .................... void main() { 0004: CLRF 04 0005: MOVLW 1F 0006: ANDWF 03,F 0007: BSF 03.5 0008: BSF 1F.0 0009: BSF 1F.1 000A: BSF 1F.2 .................... Result=PORTA*4; 000B: BCF 03.5 000C: RLF 05,W ;Rotate left PORTA and put result into W 000D: MOVWF 20 ;W->Result 000E: RLF 20,F ;Rotate left Result 000F: MOVLW FC ;MOVLW+ANDWF for clearing bits 0 and 1 in Result (I suppose it's because the carry bit can be 1, and we always want 0 after rotating 0010: ANDWF 20,F .................... } 0011: SLEEP
Conclusions
- Multiply by a power of two should be done by rotating registers to the left
Category: CCS PCM Outputs
