Newbie question on Pic18F25k20 - Setting PORTA,B as digital output

[hbrault]

Hi all,
I feel pretty silly: I can't turn PORTA and PORTB to all digital output on a Pic25K20!
What did I overlook?
I am new to using C on a Pic, so I thought the problem was C related, therefore I also wrote the program in ASM. Unfortunately the problem remains the same.

#include <p18cxxx.h>

void main (void)
{
    // Disable all Analog inputs
    ANSEL = 0;
    ANSELH = 0;

    // PORTS A,B and C are all Outputs
    TRISA = 0;
    TRISB = 0;
    TRISC = 0;
    // Set All the bits
    PORTA = 0xFF;   // PORTA is set to 0xD0  instead of 0xFF, LATA too
    PORTB = 0xFF;   // PORTB is set to 0xF6  instead of 0xFF and LATB to 0xE0 
    PORTC = 0xFF;   // Yeah! PORTC and LATC both get 0xFF
    while (1) {}
}

and now for the ASM version (identical code, identical problem)

    list      p=18f25K20          ; list directive to define processor
    #include <p18F25k20.inc>      ; processor specific variable definitions

ResetCode    org    0x000
    goto    Main

HighInteruptCode    ORG     0x008   ; High Interrupt vector address
    retfie FAST                     ; return from interrupt

LowInteruptCode    ORG     0x0018   ; Low interrupts vector address
    retfie                          ; return from interrupt

Main
    ; Disable all Analog input
    clrf    ANSEL
    clrf    ANSELH

    ;PORTS A,B and C are all Outputs
    clrf    TRISA
    clrf    TRISB
    clrf    TRISC

    ; Set All the bits
    setf    PORTA   ; PORTA is set to 0xD0, LATA too
    setf    PORTB   ; PORTB is set to 0xF6 and LATB to 0xE0
    setf    PORTC   ; Yeah! PORTC and LATC get 0xFF

LoopHere
    bra     LoopHere
    END     ; end of program

I looked at the values of some other related SFR (the ones I could think of):
ADCON0 = 0x00 (ADC is disabled)
ADCON1 = 0x00 (Vref- and Vref+ not used)
CCP1CON = 0x00 (Capture/Compare/PWM off)
CCP2CON = 0x00 (ditto)

I am now running out of ideas, any suggestion will be welcome.

Thanks

 

[nickelflippr]

These newer 18fxxKxx devices have switched some of the standard SFR's around. So clr CM1CON0 and CM2CON0 to get PortA up and running. On PortB its a config thing now, so set PBADEN=OFF to get that to digital output.

 

[be80be]

CM1CON0 and CM2CON0 But the data sheet doesn't say you need to do that for portA

But it looks like they forgot that LOL

 

[nickelflippr]

Huh, both the CMxCON0 and the CCPxCON registers are zero on reset, so that's probably not it. The O.P.'s register read says the analog pins are active PortA = 0xD0 or 0b11010000, so why doesn't clrf ANSEL and clrf ANSELH work? With the larger K22 devices it is ANSELA and ANSELB.

EDIT: I know when writing to a Port you should use LATA=0xFF, not sure if it affects this example though.

 

[be80be]

This is the only thing I see wrong you set tiris first then ANSEL

#include <p18cxxx.h>
 
void main (void)
{
    // Disable all Analog inputs
    TRISA = 0;
    TRISB = 0;
    TRISC = 0;
    ANSEL = 0;
   
 
    // PORTS A,B and C are all Outputs
   
    // Set All the bits
    PORTA = 0xFF;   // PORTA is set to 0xD0  instead of 0xFF, LATA too
    PORTB = 0xFF;   // PORTB is set to 0xF6  instead of 0xFF and LATB to 0xE0 
    PORTC = 0xFF;   // Yeah! PORTC and LATC both get 0xFF
    while (1) {}
}

 

[hbrault]

First, thank you all for your quick replies.
Second, I am a schmuck. I wasted your time and I apologize.

The chip works just fine (at least as expected on something this trivial).
The bug was in the MPLAB simulator, I was using an older version: 8.30, I updated to v8.70 and tada!

And by the way nickelflippr, you are right: there is no need to clear the CMxCON0 and CCPxCON registers: they are 0 on reset.