pic16f877 help

hey there,
i really need some help in the general area of PIC 16f877. i am using
the PICDEM 2 plus board that comes with the mplab icd 2 in circuit
debugger.
the code below is a simple code but i am unfamiliar with the coding as
i have just started assembly.

what does it all mean?

list p=16F877
#include <p16F877.inc>
__CONFIG _CP_OFF & _WDT_OFF & _BODEN_OFF & _PWRTE_OFF & _HS_OSC &
_WRT_ENABLE_ON & _LVP_OFF & _DEBUG_OFF & _CPD_OFF

; '__CONFIG' directive is used to embed configuration data within .asm
file.

;***** VARIABLE DEFINITIONS

ctr0 equ 0x20
ctr1 equ 0x21
ctr2 equ 0x22
ctr3 equ 0x23
work equ 0x24

;**********************************************************************


org 0x000 ; processor reset vector
clrf PCLATH ; ensure page bits are cleared
goto main ; go to beginning of program

main ;beginning of the program
banksel TRISB ;select the bank containing TRISB
movlw 0xf3 ;port B is the o/p
movwf TRISB ;
banksel PORTB ;select the bank containing TRISB

movlw 0x08
movwf work
movlw 0xf0
movwf PORTB
movlw 0xf4
movwf PORTB

mainlo movlw 0xff
movwf ctr2
loop1 movlw 0xff
movwf ctr0

loop decf ctr0,1
bnz loop
decf ctr2,1
bnz loop1

movf work,0
movwf PORTB
comf work,1 ; toggle led's

movf work,0
movwf PORTB
comf work,1

goto mainlo

END ; directive 'end of program'

because i am just trying to display the nightrider effect with the LEDs
but its a little more difficult than i thought.
any help would be much apprieciated,

Regards,

Colm

 

what does it all mean?

Um, well, that could involve an incredibly long answer... but I would
suggest you're better of consulting the many, many excellent and useful
technical resources available from the microchip website... starting
with the datasheet for the 16F877. In the back is an explanation of the
instructions, that will at least give you the jist of what command like
movf do.

 

oh yeah... and if all you want to do is flash LEDs, then you've wasted
a lot of money my friend!

Try www.picaxe.co.uk for something that is far easier to code and much
cheaper to program. Two resistors and a serial cable = PICAXE
programming circuit!