Reset pin on picaxe 40X2

Dicky Mint

Senior Member
Hi All,

Just a straightforward question about the 40x2 picaxe.

Is the reset pin pulled high by a 4.7k resistor for normal usage and pulled momentarily low to reset?

If so perhaps the pin should be more correctly labelled reset 'bar'?

Lacking the knowledge and time to find the way to represent the 'bar' graphically!



Senior Member
The Pin in question is actually the 25151 Pin and is accurately represented in the related PIC datasheet with an overbar. When in question, it is generally a good idea to refer to the Microchip Datasheet for the related Picaxe Chip.

(I did the above in MS Paint, manually added the bar, then inserted here as an image)

Dicky Mint

Senior Member
Thanks all, especially Phil!

Like the exhaustive answers to a question that was never actually asked!

Good to see attention to detail is not yet dead!

Just to double check, the RESET pin should be labelled Řēšēť?

Or not?



Technical Support
Staff member
Perhaps the pin should be more correctly labelled reset 'bar'?
There's no definitive answer to that. "RESET which is active low" is correct but some sort of indication of it being an active low is often applied when shown as just a name, but not always. "/RESET" and "RESET/" are sometimes used, sometimes '\' is used instead of '/', and I have even seen '-RESET' for some devices..

While "RESET" with a line above it has been common in some circuit diagrams it has never been that suitable for use in text, which is why the "/" notation evolved, and that now often gets used in circuit diagrams . There's also the inevitability of people using whatever they want to use regardless of how a device shows it., issues of consistency. There can be confusion no matter what one does.

Some favour giving active low signals active high naming so would use "RUN" instead of a "RESET" variant. I have never particularly liked that approach.

So there's no agreement on what it should be, always a debate on what it should be and which is best. It's perhaps worth noting that the datasheet I have for the venerable NE555 has its active low reset labelled simply as "RESET" so the practice seems long standing.

Dicky Mint

Senior Member
Interesting Hippy

Having used the NE555 more than a few times its particularly interesting that I didn't notice that exactly the same applies to it, too.

We live and learn.