08M 4MHz vs 8MHz

[wapo54001]

In using the 08M, has anyone ever found any reliability issue whereby running the chip at 4MHz was more reliable than running it at 8MHz all else being equal?

If yes, could you elaborate, please?

Thanks!

 

[hippy]

I've never noticed any problems with any PICAXE at 8MHz and I usually run them at 8MHz when I can.

Any specific problem you could elaborate on yourself ?

 

[wapo54001]

Hippy, thank you for the reply.

No, I myself have not had a problem on the very few times that I've run the 08M at 8MHz, but I wanted to ask folks with more experience because at this point I'm putting together an application where reliability is far more important than speed, and I'll stay at 4MHz if there is any inkling of a reliability hit at 8MHz.

Still, the faster clock will make the system seem more responsive and so is desirable, but only if reliability remains unaffected.

 

[manuka]

Ditto for me- always rock solid at 8MHz. However "½ times" etc at 8MHz are inconvenient,so 4MHz is usually more straightforward!

 

[hippy]

I don't think that you'll have any problems. There will be a slightly higher current drain at 8MHz than at 4MHz but I wouldn't expect it to be significant.

 

[wapo54001]

My circuit is controlled by an 08M, and includes a 2N7000 with integrator circuit to precision-control an output voltage plus a power mosfet circuit to sink warning light current. Total current draw with everything working seems to be about 4ma not including the sensor and LCD readout. I think I can afford a slight increase to run at 8MHz.

I will try the 8MHz tomorrow. It'll require changing some timing "pause" values, but shouldn't be too hard.

Thanks for the comments.