PIC16F527 don't do nothing...

[Demon]

I use this order, might not make a difference but I like structure (old mainframe programer):

Configs
DEFINES
Special registers
TRIS
Ports
Variables

Robert

[mtripoli]

I'm posting a follow-up to this in case it may help someone else. Though I'm really not happy with this device (the clock jitter in INTOSC mode is too severe for my tastes) here's what I've found out. It appears that BANKSEL does not work on this device. Not sure why; I've reported it to the guys at meLabs and I'm sure they'll get to the bottom of it. In the meantime, assembly to the rescue. If you are not aware of it, there are two things I got from this exercise:

1.) A friend had to remind me that going back to the early days of the '54, there wasn't a TRIS register; there was a TRIS command. This device, being part of the 12-bit core series, uses the TRIS command. So, you load "W" with the value you want TRIS to be, and then use the TRIS command to set the I/O. No big deal, as long as you're aware of it. You can see it in the code.

2.) BANKSEL doesn't work (nor does BSR). There is in fact, yet again, a command for this: MOVLB - move literal to BSR.

Once past those two things, things started looking up (the attached code compiles and runs fine). One thing to keep in mind, generally speaking with any of the devices that have alternate functions on a pin (in other words, all PIC's); set these functions prior to setting TRIS, otherwise these functions will trample on TRIS. Or bit select them, however you like to code. I'm spoiled by the PIC16F1xxx series, and if it wasn't for the fact that these "smaller" devices are so cheap, would use them for everything.

'****************************************************************
'*  Name    : LED_003.BAS                                      *
'****************************************************************
;#CONFIG
;    __config _FOSC_INTRC_CLKOUT &_WDTE_OFF &_CP_OFF &_MCLRE_ON &_IOSCFS_8MHz &_CPSW_OFF &_BOREN_ON &_DRTEN_OFF
;#ENDCONFIG

DEFINE  OSC 8


;ALIASES


LED    VAR PORTC.0          ; OUTPUT - DIGITAL


;PORT CONTROL REGISTERS
 
    asm
    MOVLB   b'00000000'     ; SELECT BANK 0
    
    MOVLW   b'00000000'	       
    MOVWF   ADCON0

    MOVLW   b'00000000'	       
    MOVWF   INTCON0

    MOVLW   b'00000000'	       
    MOVWF   INTCON1

    MOVLB   b'00000001'     ; SELECT BANK 1

    MOVLW   b'00000000'	       
    MOVWF   CM1CON0

    MOVLW   b'00000000'	       
    MOVWF   CM2CON0

    MOVLW   b'00000000'	       
    MOVWF   VRCON
    
    MOVLB   b'00000010'     ; SELECT BANK 2

    MOVLW   b'00000000'	       
    MOVWF   ADCON0
    
    MOVLW   b'00000000'	       
    MOVWF   INTCON0
    
    MOVLW   b'00000000'	       
    MOVWF   INTCON1
    
    MOVLB   b'00000011'     ; SELECT BANK 3

    MOVLW   b'00000011'	       
    MOVWF   OPACON        

    MOVLW   b'11001101'
    MOVWF   ANSEL
    
    MOVLB   b'00000000'
    
    MOVLW   b'00010101'	    ; LOAD W    
    TRIS    06h             ; LOAD TRIS PORTA 

    MOVLW   b'00010000'	    ; TRIS  PORTB   
    TRIS    07h
    
    MOVLW   b'11000000'	       
    TRIS    08h    
    endasm


    low led
 

MAIN:
    HIGH    led    
    pause   250
    low     led
    pause   250
    goto    main
    
    
    end