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

1 generally reads a details sheet in a person of two techniques. The initial is to get every spec at experience value, figuring that the engineers have taken everything into account and presented every single selection as the absolute limit that will protect against the Magic Smoke from escaping. The other way is to throw out the data sheet and just try out whatsoever you want, figuring that the engineers played it as safely and securely as feasible.

The latter situation would seem to have been the commitment guiding pushing an ATtiny way, WAY outside of what the spec sheet says is feasible. In accordance to [SM6VFZ], the specs on the ATtiny817 demonstrate that the 12-little bit timer/counter D (TCD) should be restricted to a measly 32 MHz highest frequency, above which a person is supposed to utilize the counter’s inside prescaler. But by working with a 10-MHz precision frequency generator as an external clock, [SM6VFZ] uncovered that inputs up to somewhat above 151 MHz were countable with 1-Hz precision. Earlier mentioned that stage, items began to drift, but which is even now quite wonderful overall performance from something cobbled together on an eval board in a decidedly suboptimal way.

We’d consider this end result could lead to some intriguing assignments, considering the fact that the undocumented restrict for this timer places it effectively within range of various novice radio allocations. Even if it doesn’t demonstrate beneficial, that is Okay — just seeing how considerably factors can be pushed is great way too. And it’s not like this is the to start with time we’ve caught [SM6VFZ] persuading an ATtiny to do abnormal things, either.