On Fri, Jul 27, 2001 at 02:55:36PM +0100, David Stubbs wrote:
> Hey,
>
> I asked about some 16f84's at a shop a bit ago and they told me they were no
> longer in production but a 16f84a version is available. I haven't had time
> to properly look through the 16f84a's data sheets yet but want to know the
> main differences. The only difference I know is that a 20MHz version is
> available, where I believe a 10MHz was the max for the non A one.
>
> One main issue though, Is it exactly the same to write the program to it? (I
> use my own software to program it)

Just a friendly piece of advise on the subject. Don't use the 16F84a parts.
Microchip is clearly trying to put them into an end of life state.

The alternative is the 16F628. Readily available at Digikey. Here's the scoop.

- Twice the program memory
- Three times the data memory
- three timers vs. 1 for the 16F84a
- two comparators vs. 0 for the 16F84a
- twice the data eeprom memory
- hardware USART
- up to 3 extra I/O pins.
- 4 Mhz internal osciallator.
- Runs up to 20 Mhz.
- Can be low voltate programmed.

And you get this all at 2/3 the price of a 16f84a. That's right. The part
costs a lot less. At digikey the 16f84a is $6.00. The 16F628 is $3.88 in the
20 Mhz version.

The parts are both pin and programming compatible. Be sure to check for any
differences in the config word though.

Considering that you get a whole bunch more for a whole lot less, I can't see
any reason to purchase 16F84a parts anymore. And considering the pricing, I'm
pretty sure that's what Microchip expects.

BAJ

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