December 8, 2022

Onthebus-Project

Empowering People

To Turn An ATtiny817 Into A 150MHz Counter, First Throw Out The Spec Sheet

To Turn An ATtiny817 Into A 150MHz Counter, First Throw Out The Spec Sheet

Just one usually reads a facts sheet in one particular of two techniques. The very first is to consider every spec at facial area worth, figuring that the engineers have taken every little thing into account and offered each individual number as the absolute limit that will stop the Magic Smoke from escaping. The other way is to toss out the info sheet and just consider whatever you want, figuring that the engineers played it as safely as achievable.

The latter circumstance appears to be to have been the enthusiasm behind pushing an ATtiny way, WAY beyond what the spec sheet states is achievable. According to [SM6VFZ], the specs on the ATtiny817 demonstrate that the 12-little bit timer/counter D (TCD) should be constrained to a measly 32 MHz utmost frequency, over which 1 is meant to utilize the counter’s inside prescaler. But by utilizing a 10-MHz precision frequency generator as an external clock, [SM6VFZ] observed that inputs up to marginally higher than 151 MHz ended up countable with 1-Hz precision. Above that stage, matters started off to drift, but that is however pretty good overall performance from anything cobbled alongside one another on an eval board in a decidedly suboptimal way.

We’d envision this consequence could direct to some appealing jobs, since the undocumented limit for this timer places it very well inside range of multiple novice radio allocations. Even if it does not verify valuable, that’s Okay — just looking at how far factors can be pushed is cool as well. And it’s not like this is the initial time we have caught [SM6VFZ] persuading an ATtiny to do unconventional issues, possibly.