'New Pic Wishlist'
A belated addition to the new products wishlist.
I would like to get two bit operated instructions that are able
to move a bit (or an inverted bit) from a given file, bit to another
given file, bit in a single instruction (without having to use 4 ops
and having a 2 cycle uncertanty in the instant the move takes place).
I would settle for a move from the status file to the file pointed to
by the FSR as I can see a shortage of bits, inversion of the bit would
be useful STATUS,b -> [FSR],b and direction from [FSR],b -> STATUS,b,i
as well. This would
only be 2 new instructions and would make highspeed bit manipulations
possible. Currently one needs a lot of pre-work to move one bit into
an output at an exactly timed instant. (by a lot of prework I mean 3
ops typically to read, get a literal and mask out bits, sometimes more if
you do not know what the other bits will be)
Alternatively the moves could be from immediately declared files
5, 6, 7 & 8.
IMM,b -> [FSR],b,i
[FSR],b -> IMM,b,i
That would be 2+3+3+1 bits of literal a total of 9 which should be
possible to sneak in to the opcodes on a 14 bit PIC.
This would also be useful for high speed interrupts.
A 50 MHz PIC would also be cool, C54 or C74 would be sufficient.
Kalle Pihlajasaari data.co.zakalle
Interface Products Box 15775, Doornfontein, 2028, South Africa
+27 (11) 402-7750 Fax: +27 (11) 402-7751
Hi at the piclist,
To my opinion the interruptresponse time is prolonged unneccessarily
by saving the flags and working file (the trick with SWAP .. there
is an application note about it...)
I don't know if somebody has already requested the instruction (or
Microchip has even announced it):
I would like to see a single instruction to push and pop both
registers in a device like the 16C84 or 16C71.
(Or even better (though maybe not easy to implement):
The optimum would be kind of REFFIEWF which restores the registers
in a single instruction when returning from interrupt.
And the Flags and W File already saved
when the PIC starts executing at 004 (the interrupt adress))
; Frieder Ferlemann
; Institut fuer Umweltphysik
; Im Neuenheimer Feld 366, Zi 410
; D-69120 Heidelberg
; Tel.: 06221 563385 oder 563334
; Fax: 06221 563405
; Email: uphys1.uphys.uni-heidelberg.deFE
; To be scanned by BundesNachrichtenDienst: Embargo, G3, Police
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