gnupic: Re: [gnupic] Cannot get 18f252 to blink
Subject:
Re: [gnupic] Cannot get 18f252 to blink
From:
Edward Tiong ####@####.####
Date:
24 Oct 2006 20:06:27 +0100
Message-Id: <200610241306.25487.etiong@ece.ualberta.ca>
I think that you are not in proper banks when addressing the TRISA etc
you may want to add in the following lines
> ;Inits
banksel ADCON1
> movlw b'00000110'
> movwf ADCON1 ;sets POARTA pins as digital I/O
banksel TRISA
> movlw b'11111110' ;Set the RA0 pin
> movwf TRISA ; to output.
> movlw b'11111111'
> movwf TRISB
> movlw b'00000000'
> movwf TRISC
>
Also further in your code ...
> flash_led
banksel PORTA
> movlw b'00000001'
> xorwf PORTA,f
Ed
On Tuesday 24 October 2006 12:17, David Froseth wrote:
> I am having problems getting a 18f252 to flash an LED. I am using a
> PICSTART Plus with a Keyspan usb-serial adapter. I am using gpasm and
> picp with OS X. This setup has worked for the 16f84a and the 16f870 chips.
> I have written this simple .asm program which compiles to a .hex file
> successfuly:
>
> ;Title: 0.1flash252
> ;File Saved As: 0.1flash252.asm
> ;Clock Frequency: 4 MHz
> ;PIC chip: 18F252
> ;
> ;Description:
> ;
> ;testing RA0 flash with 18f252;
> ;
> ;
> ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
> ;Processor type::
>
> processor 18f252
>
> ;List file directives
>
> list p=18f252
>
> ;SFR equates and other 18fxxx specific declarations
>
> include "/sw/share/gputils/header/p18f252.inc"
>
> ;Configuration bytes
>
> __config _CONFIG1H, b'00100001' ;XT oscillator
> __config _CONFIG2L, b'00001110' ;enable power-up timer
> __config _CONFIG2H, b'00001110' ;watchdog timer disabled
> __config _CONFIG3H, b'00000001' ;CCP2 on RC1
> __config _CONFIG4L, b'10000001' ;Disable LVP
>
> ;All other configuation bits involve code protection.
> ;Default to protection-off (logic 1)
>
>
>
> radix dec
>
> ;;;;;;;;;;;;;;;;;;;;;;;;;;
> outer_delay equ 0x20 ;First counter
> inner_delay equ 0x21 ;Second counter
>
> ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
>
> org 0x0000
> goto MainLine
>
> ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
> ;High-priority interrupt service routine:
> org 0x0008
>
> ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
> ;Low-priority interrupt service routine:
> org 0x0018
>
>
>
> ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
> ;Main body of the program
> MainLine
>
> ;;;;;;;;;;;;;;;;;;;;;;;;
> ;Inits
> movlw b'00000110'
> movwf ADCON1 ;sets POARTA pins as digital I/O
> movlw b'11111110' ;Set the RA0 pin
> movwf TRISA ; to output.
> movlw b'11111111'
> movwf TRISB
> movlw b'00000000'
> movwf TRISC
>
> ;;;;;;;;;;;;;;;;;;;;;;;;
> ;Start
>
> flash_led
> movlw b'00000001'
> xorwf PORTA,f
> call debounce
> goto flash_led
>
> ;;;;;;;;;;;;;;;;;;;;;;;;
> ;Subroutines
>
> debounce
>
> movlw 0xff
> movwf outer_delay
>
> load_debounce_inner_delay
>
> movlw 0xff
> movwf inner_delay
>
> decr_debounce_loop
>
> decfsz inner_delay,f
> goto decr_debounce_loop
> decfsz outer_delay,f
> goto load_debounce_inner_delay
> return
>
> end
>
> _______________________________
>
> The .hex file is :
> :020000040000FA
> :040000000CEF00F011
> :08001800060EC16EFE0E926E91
> :10002000FF0E936E000E946E010E801A1AEC00F013
> :1000300014EF00F0FF0E206EFF0E216E212E1EEF3A
> :0A00400000F0202E1CEF00F012006B
> :020000040030CA
> :08000000FF210E0EFF0181FF3C
> :00000001FF
>
> When I read the program memory out of the chip, I get:
>
> $ picp /dev/tty.KeySerial1 18f252 -rp
>
> :020000040000FA
> :10000000040E0060000E926E9200000E000E0000C2
> :10001000010C0000000000000000000000000000D3
> :10002000000000000000000E000000000020006042
> :100030000000000000000000020E016C0020046EB1
> :100040000000000E004000000000012E250E0020E0
> :10005000002023EF00F0020026EF00F0082E24EF2E
> :1000600000F0052E22EF00F0120037EF00F00150F3
> :10007000806E1200FFFFFFFFFFFFFFFFFFFFFFFF8C
> :10070000F9263F0C060C5B0C4F0C660C6D0C7D0C37
> :10071000070C7F0C6F0C400CFFFFFFFFFFFFFFFF7C
> :00000001FF
>
> This obviously does not look the same. Is this normal? Other chips
> that are working show program memory reads that are different than the
> .hex file, also. I know nothing about how .hex files work.
> Can anybody help me get my 18f252 to blink? What am I missing?
>
> Thanks
>
>
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