Counting Number of Occurrences

This PIC Microcontroller project is used to count the occurrence of a given number from a set of numbers stored in the Instrumental Model - Parallel Pattern with Interrupt. To simulate this circuit, initially activate Mixed Mode simulator from the Schematic Editor window. Simulation can be performed by selecting Run Transient analysis (Oscillograph) from Simulation menu.

The circuit contains a PIC Microcontroller, Parallel Pattern with Interrupt, Binary to 7 Segment Decoder/Driver, Seven Segment LED Display.

PortA and PortB is set as Input Port.PortC is first set as Input Port and after reading the number to be checked, it is changed to Output Port. Whenever the interrupt signal goes low, PortB starts reading the data from the Parallel Pattern model. The count showing the occurrence of the given number after all the comparisons will be available in PortC and it will be displayed through the Seven Segment Display.

The source code written in Assembly language can be viewed from the code editor window

The program is as shown:

include "p16c5x.inc"

TEMP_VAR UDATA

c_data RES 1

count RES 1

startup code

start movlw 0xff ;moving literal constant 0xff to W

tris PORTA ;setting PORTA in input mode

tris PORTB ;setting PORTB in input mode

tris PORTC ;setting PORTC in input mode

movf PORTC,1 ;reading through PORTC

movf PORTC,0 ;moving the read value to W

movwf c_data ;moving the value to c_data

movlw 0x00 ;moving literal constant 0x00 to W

tris PORTC ;setting PORTC in output mode

bchk btfsc PORTA,3 ;checking whether RA3 pin is clear or not

goto bchk ;if not

d_read bcf PORTA,3 ;if yes, blocks further read

movf PORTB,1 ;reading through PORTB

movf PORTB,0 ;moving the read value to W

xorwf c_data,0 ;xoring the data with the value stored in c_data

btfsc STATUS,2 ;checking whether zero flag is clear or not

incf count,1 ;if not

movf count,0 ;if yes, the value stored in count is moved to W

movwf PORTC ;outting the value through PORTC

bsf PORTA,3 RTA,3 ;setting the RA3 pin HIGH

goto bchk ;again goes to bchk

goto start ;repeat

end

The source code in the code editor window has to be compiled after making any modifications

(editing). Also the code can be debugged during simulation.