Package: sdcc
Severity: wishlist
in pic14 and pic16 (actually i need pic14 - 16f877)
i would like to see support for the "dt" instruction.
"dt" is an extremely commonly used technique for accessing
arrays:
movlw HIGH ARRAY
movwf pclath; /* loads top bits of ARRAY into pclath */
movf index,w;
call ARRAY;
movwf destination;
mov
ARRAY:
addwf pcl, f; /* adds program counter to f(!) */
dt "0123456789abcdef",0; /* returns data pointed to by pctr! */
two key things are required to pull this off:
1) support for "HIGH" qualifier in pic14 peephole instruction
analysis
2) support for dt instructions.
this is a _standard_ technique for accessing static arrays
that is well-documented, and several examples, including pdf
presentations, can be found easily by searching for "pic dt
p16f877" on google.com.
mpasm has this behaviour automatically as part of its optimisation.
-- System Information:
Debian Release: testing/unstable
Architecture: i386
Kernel: Linux highfield 2.6.10-1-686 #1 Tue Jan 18 04:34:19 EST 2005 i686
Locale: LANG=C, LC_CTYPE=C
--
To UNSUBSCRIBE, email to [EMAIL PROTECTED]
with a subject of "unsubscribe". Trouble? Contact [EMAIL PROTECTED]
