On 19/2/2012 2:40 AM, Peter wrote:
> I found some balky jal generated pic code which was disassembled by me to=
 yield
> the use of what appears to be an undocumented instruction, used as in:
>
>    0821  movf     0x21, w ; load w with data from reg. 0x21
>    0065  tris     0x65    ; undocumented instruction

Do you know which version of the Jal compiler and which libraries=20
created this code? I checked the libraries (as I said, the compiler by=20
itself would never generate a TRIS instruction): the stone-age library=20
(written by me, in the days that all 14-bit cores supported TRIS=20
instructions) does use it, because the library file jpic.jal had=20
constructs like

procedure _trisa_flush is
    assembler
       bank movfw trisa
            tris  5
    end assembler
end procedure

The current library files for 14-bit cores should not generate the TRIS=20
instruction, instead they use bank switching:

var volatile byte   TRISA                     at { 0x85 }
var volatile byte   PORTA_direction           at TRISA

Of course, the current library still uses TRIS for 12-bit cores:

procedure PORTA_direction'put(byte in x) is
    pragma inline
    _TRISA_shadow =3D x
    asm movf _TRISA_shadow,W
    asm tris 6
end procedure

--=20

Wouter van Ooijen

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