PIC16F684 Part 010 - Optimizing Code and RRF Instruction

PIC16F684 Part 010 - Optimizing Code and RRF Instruction
Watch my 74HC595 Shift Register (Serial in Parallel Out) video: • 74HC595 Shift Register...
See the 74HC595 datasheet: www.ti.com/lit...
PIC16F684 datasheet: ww1.microchip....

[@2bit661]

;free sample code. copy and paste.
processor 16F684
include "p16f684.inc"
; Configuration settings
__CONFIG _INTRC_OSC_NOCLKOUT & _WDT_OFF & _MCLRE_OFF
R1 EQU 0x20 ; outer loop counter
R2 EQU 0x21 ; inner loop counter
C1 EQU 0x22 ; specify file to store counter value
BIT_COUNTER EQU 0x23 ; counter for bit testing
; Define connections
#define SER_IN PORTA, 0 ; RA0 connected to 74HC595 SER_IN
#define L_Clock PORTA, 1 ; RA1 connected to 74HC595 L_Clock
#define Clock PORTA, 2 ; RA2 connected to 74HC595 Clock
; Main program start
org 0x0000
goto Initialize
; Main program
Initialize:
; Initialize ports
bsf STATUS, RP0 ; Switch to Bank 1
clrf ANSEL ; Set all pins to digital
clrf TRISA ; Set all pins of PORTA as output
bcf STATUS, RP0 ; Switch to Bank 0
LOOP:
MOVLW B'11101010'
MOVWF C1
CLRF BIT_COUNTER

BITTESTER:
BCF SER_IN ; Clear SER_IN initially
MOVF BIT_COUNTER, W
BTFSC C1, 0
BSF SER_IN ; Set SER_IN if the corresponding bit in C1 is 1
CALL DELAY
CALL SHIFT_CODE

; Shift C1 right by 1 bit
RRF C1, F ; rotate right f through carry
INCF BIT_COUNTER, F
MOVLW 8
SUBWF BIT_COUNTER, W
BTFSS STATUS, Z ; Check if BIT_COUNTER == 8
GOTO BITTESTER ; Repeat until 8 bits are tested

BSF L_Clock ; L_CLOCK (PORTA, 1) sets or latches previously-sent 8 bits
CALL DELAY
BCF L_Clock ; L_CLOCK cleared back to low
CALL DELAY

GOTO LOOP
SHIFT_CODE: ; shift register subroutine
BSF Clock ; Clock pin (PORTA, 2), clocks in whatever serial input (PORTA, 0) is doing
CALL DELAY
BCF Clock
CALL DELAY
BCF SER_IN
CALL DELAY
RETLW 0
DELAY:
MOVLW 0xFF
MOVWF R1
AGAIN:
MOVLW 0xFF
MOVWF R2
HERE:
NOP
NOP
DECFSZ R2, F
GOTO HERE
DECFSZ R1, F
GOTO AGAIN
RETLW 0
END ; Needed to end the program.

[@yuvarajcena26]

6502 cpu

[@2bit661]

Thanks for your comment. I searched UA-cam for "6502 cpu" and found this video: ua-cam.com/video/acUH4lWe2NQ/v-deo.html
Wow! I didn't realize such a chip was so popular and widely used.
I am learning too. I didn't realize hobbyists can program these chips: ua-cam.com/video/k1iv2ANb2Ko/v-deo.html
Of course, I am using a PIC Microcontroller in my experiments. The Microchip PIC Chips are different. Maybe you knew that. The software for PIC chips is MPLAB. Thanks for your comment. Have a nice day.