Breadboarded first circuit with Picmicro, wrote a test program
in Mplab / Mpasm. Runs/assembles sucessful in Mplab sim
w/watch windows etc.
Programed chip using a Micro Engineering Labs EPIC programer.
Circuit has 8 leds on portb, when powered up all leds light up
(portb high, not what it is supposed to do). Thought it was a
problem with my circuit or one of the parts etc. After changing
parts, testing etc., for the fun of it I took a demo program that came
with the programer made some changes assembled it using melabs Pic Macro
Assembler program and programed the chip and the circuit worked just like
it is suppose to? Tried many changes to program in Mplab/Mpasm and
reprograming the chip with the same results (runs well in sim, but does
not run in circuit) and program demo from melabs works. I must be missing
something. I really want to use Mplab/Mpasm for developing. I have
included the code below, any help would appreciated. I'm using;
PIC16F84A-20, Mplab v4.12.12, EPIC programer from Micro Egineering Lab.
***************************************************************
#1)below program from Mplabs - (crude, should work but does not)
email may have played with tabs and line length
***************************************************************
 list      p=16F84A
 include <p16f84a.inc>

 __CONFIG   _CP_OFF & _WDT_OFF & _PWRTE_ON & _HS_OSC

portb   equ     0x06
count   equ     0x0c
;---------------------------
            org       0x000
;
start   movlw   0x00    ;load W with 0x00
           tris       portb     ;copy W tristate, port B outputs

           clrf       portb     ;all lines low
;

           bsf        portb,0   ;turn on led

go            bsf             portb,0   ;turn on led
           call       delay     ;delay via sub
           bcf        portb,0   ;turn off led
;
           bsf        portb,1   ;turn on led
           call       delay     ;delay via sub
           bcf        portb,1   ;turn off led
;
           bsf        portb,2   ;turn on led
           call         delay   ;delay via sub
           bcf        portb,2   ;turn off led
;
           bsf        portb,3   ;turn on led
           call         delay   ;delay via sub
           bcf        portb,3   ;turn off led
;
           bsf        portb,4   ;turn on led
           call       delay     ;delay via sub
           bcf        portb,4   ;turn off led
;
           bsf        portb,5   ;turn on led
           call         delay   ;delay via sub
           bcf        portb,5   ;turn off led
;
           bsf        portb,6   ;turn on led
           call       delay     ;delay via sub
           bcf        portb,6   ;turn off led
;
           bsf        portb,7   ;turn on led
           call       delay     ;delay via sub
           bcf        portb,7   ;turn off led
;
           goto go            ;repeat
;
delay   movlw   0x02    ;decimal 10
            movwf       count   ;load counter
repeat  decfsz  count,f ;decrement counter
           goto repeat  ;not 0
           return                     ;counter 0, end delay
;
 end
************************************************************
#2) below from melabs demo (assembled w/ Pic Macro Assembler)
This code works.
email may have played with tabs and line length
*************************************************************
        maclib  'p16f8x.inc'
;
        device  pic16f84,hs_osc,wdt_off,pwrt_on,protect_off
;
leds    =       portb           ;led output port
;
dir_b   =       00h             ;all out
;
          org     0ch             ;start of ram space
;
binary  ds      1               ;binary count
cnt_low ds      1               ;delay counters
cnt_mid ds      1
cnt_high ds     1
;
       org     0               ;reset vector
;
        jmp     start           ;go to beginning of program on reset
;
       org     5               ;start of code space
;
           retw    'DEMO84 Rev 1.3'
;
;
; delay for about 1 second based on 4mhz clock cycle
;
delay    mov     cnt_high,#4
       clr     cnt_mid
       clr     cnt_low
delay1  nop
       djnz    cnt_low,delay1
       djnz    cnt_mid,delay1
        djnz    cnt_high,delay1
        ret
;
;
; it all starts here
;
start     mov     leds,#0         ;start with all leds off
           setb    rp0             ;point to register page 1
           mov     trisb,#dir_b    ;set port b data direction register
           clrb    rp0             ;point back to register page 0
;
;
; main loop to send binary sequence to port b
;
        mov     binary,#1       ;start with first led on
;
mainloop mov    leds,binary     ;send the binary count to the leds
;
              call    delay           ;wait around a second
;
              inc     binary          ;increment to next binary value ;
              jmp     mainloop        ;do it forever
;