At 21:16 14/09/99 +1200, you wrote:
>Hi,
>
>I use PIC's and 8051's.  In both cases I program in C, so the
>instruction set doesn't matter too much to me.
>
>I tend to go for PIC's for my smaller projects because the I/O
>structure is much more felexible.  8051 I/O usually outputs logic
>high during reset which can be a pain, as well as having weak pull
>ups all the time, and this can mean more external hardware
>considerations.

This is not quite so, the 8051 has "Quasi bi-directional" ports. This means
that it has 100K sort of thing always pulling the pin up, it is able to
sink 20mA, so you are nominaly forced to design active low (Not a bad idea
at any time)

The 8051 is great for largish projects that require the I/O it can provide.
The 8051 is harder on current, but the monimally better peripherals make
this worth while. There is more than one source for the 8051 and lots of
stuff out there for them.

As for the structure being more flexable for the PIC...?

Normally it comes down to the size of the project and the intended cost


Dennis


  On chip WDT and reset also assists these small
>projects, making them much more a one chip design, but the new
>8051 compatible Philips 87LPC764 is worth a mention.
>
>My 8051 designs mostly use Atmel Flash devices now, which are
>exceptionally great for development.
>
> which are the pros and cons of selecting a PIC over a member of the 8051
>> family ?
>>
>> Is this a question of religion or are there practical differences ? :)
>>
>> Thank you
>>
>> Duilio Foschi
>>
>
>Brent Brown
>Electronic Design Solutions &
>HI-TECH Software Sales
>16 English Street
>Hamilton, New Zealand
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>
>