Re: [Flashforth-devel] AVR assembler and disassembler

[Stefan <fli...@gm...>]

Hallo Helge,

disassembled code is:

9a58 -> sbi PORTD,0 (that's 8 mod 8 because only values from 0 to 7 are
allowed)
9a5c -> sbi PORTD,4
...
because cbi/sbi use the bitnumber and not the bitmask.

use:
3 constant txd_pin
2 constant rxd_pin

greetz bitflipser


Am 31.12.2021 um 12:35 schrieb Helge Kruse:
> Hello,
>
> I'm new to FlashForth. I want to use it for ATmega328 and ATmega2560.
>
> I try to implement an ISR for a bit bang serial port, since the
> ATmega328 has only one USART. My minimum code example is:
>
> $002b constant portd
> $002a constant ddrd
> $08 constant txd    \ bit 3
> $04 constant rxd    \ bit 2
>
> \ make an I/O addres from memory address for sbi and cbi.
> : >IO  ( a - io )  $20 invert and ;
>
> : t2CompAIsr  txd portd mset  rxd portd mset  rxd portd mclr  txd portd
> mclr ;
>
> : t2CompAIsr_
>     [
>       portd >IO txd sbi,
>       portd >IO rxd sbi,
>       portd >IO rxd cbi,
>       portd >IO txd cbi,
>     ]
> ;i
>
> : irqCompAInit
>     rxd ddrd mset \ to see write to rxd
>     txd portd mset  txd ddrd mset
>
>     ['] t2CompAIsr_ compAIvec int!
>     208 ocr2a c!  \ set comparator A register
>     2 tccr2a c!   \ set CTC mode (WGM = 2)
>     6 tccr2b c!   \ activate counter 2, clock source = clk_T2S/1
>     2 timsk2 mset \ activate timer2 comparatorA interrupt OCIE2A
> ;
>
> If I use mclr/mset to set the bits, I see the changes on the pins with a
> logic analyzer. But unfortunately I can't see any change on the PORTD
> pins if I use the word t2CompAIsr_.
>
> What's wrong with my assembler code? I  want to verify what I compiled
> with the disassembler:
>
> see t2CompAIsr_
> 975a 9a58
> 975c 9a5c
> 975e 985c
> 9760 9858
> 9762 940c 3c33 jmp   ...............
>  ok<$,ram>
>
> All the CBI/SBI is not decompiled. Probably this is not implemented in
> "forth/avr/see.fs". I also tried "forth/avr/see2.fs". The later file
> can't be compiled, a word sy1 is missing.
>
> How can I verify what's wrong with my simple code?
>
> Best regards,
> Helge
>
>
>
>
>
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