Microcontrollers PIC18F course second sample using assembler

This is the second sample of my course if you interested in the course or you need help in a project (not for free) you can contact me at:
postgraduatecahg@gmail.com



list p=18f2550
  include "P18F2550.INC"
  ;Bits de configuracion
        CONFIG FOSC = HS 
; High speed clock.
        CONFIG MCLRE = OFF                ; Master Clear OFF
        CONFIG BOR = OFF                     ; Brown-out OFF
        CONFIG PWRT = OFF                  ; Power-up Timer OFF
        CONFIG LVP = OFF
        CONFIG XINST = OFF
        CONFIG PBADEN = OFF
        CONFIG CP0 = OFF
        CONFIG CP1 = OFF
        CONFIG CP2 = OFF
        CONFIG CP3 = OFF
        CONFIG CPB = OFF
        CONFIG CPD = OFF
ORG  0x00
; start from 0x00 address
GOTO START
;jump to start label.
ORG  0x50 ; space for IRS
START
movlw 0x0F; 
movwf ADCON1,0 
;PORTAandPORTB pins are digitals
clrf TRISB,0 
;PORT B as an output.
movlw b'00011111';
movwf TRISA,0
;PORT A as input
LOOP
movf  PORTA,W,0  
;Move Port A and store it in W.
andlw  0x0F    
;W = W(AND)00001111
movwf  PORTB,0; 
goto  LOOP; for make a loop
end; END of the program.

Figure 1. Circuit diagram. 

You can ask by my course in Spanish.