gnupic: Re: [gnupic] Cannot get 18f252 to blink
Subject:
Re: [gnupic] Cannot get 18f252 to blink
From:
David Froseth ####@####.####
Date:
24 Oct 2006 22:13:07 +0100
Message-Id: <453E81D1.3020503@umich.edu>
Edward,
I don't think that 'banksel' is an assembly mnemonic. Could that be a
Basic or C command?
Also, I think that with the 18f parts, all of the Special Function
Registers (0x0f80-0x0fff) and the first 128 bytes of data memory
(0x0000-0x007f) are easily accessed through the 'Access Bank'. No bank
switching is necessary. I definitely could be missing something on
this, though, since I cannot get this simple program running.
Thanks
Edward Tiong wrote:
> 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
>>
>>
>>---------------------------------------------------------------------
>>To unsubscribe, e-mail: ####@####.####
>>For additional commands, e-mail: ####@####.####
>
>
> ---------------------------------------------------------------------
> To unsubscribe, e-mail: ####@####.####
> For additional commands, e-mail: ####@####.####
>
>
>
>
