> For the sake of this discussion, let's define "core size"
> based on the registers and the add instruction.  If it has
> 16bit registers and a 16bit add instruction, it's a 16bit
> processor.  32bit registers and add makes it a 32bit processor,
> and only 8 bits makes it an 8bit core.  That makes a Z80 an 8
> bit core despite the limited double add, the 8086 a 16bit, and
> a 68000 a 32bit processor.  That makes the PIC an 8bit core
> without question...  Instruction size doesn't really matter.

In Microchip documentation the terems '12-bit core', '14-bit core', etc
are often used, so I would prefer to reserve that for the instruction
width. And I do think the instruction witdh does matter, if only for the
amount of code flash needed.

But OK, to avoid all confusion, let's talk about 'N-bit-datapath' and
'N-bit-instruction' chips.

I don't think there is much room for 16-bit-datapath chips, being
squeezed by well-established 8-bitters (PIC, 8051, AVR) and 32-bitters
like the ARM getting cheaper and available 'round the corner'.

The ARM in thumb-mode is a 16-bit-core, so I don't think its code size
will be much worse than a 14-bit-core PIC (16F's, some 12F's).

Wouter van Ooijen

-- -------------------------------------------
Van Ooijen Technische Informatica: www.voti.nl
consultancy, development, PICmicro products
docent Hogeschool van Utrecht: www.voti.nl/hvu
 

-- 
http://www.piclist.com PIC/SX FAQ & list archive
View/change your membership options at
http://mailman.mit.edu/mailman/listinfo/piclist