December 7, 2022


Melts In Your Tecnology

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

One particular typically reads a data sheet in a single of two approaches. The initially is to acquire each and every spec at deal with price, figuring that the engineers have taken anything into account and offered every single variety as the absolute limit that will reduce the Magic Smoke from escaping. The other way is to throw out the data sheet and just check out no matter what you want, figuring that the engineers performed it as safely and securely as probable.

The latter circumstance would seem to have been the inspiration behind pushing an ATtiny way, WAY further than what the spec sheet suggests is feasible. According to [SM6VFZ], the specs on the ATtiny817 present that the 12-bit timer/counter D (TCD) really should be minimal to a measly 32 MHz optimum frequency, earlier mentioned which just one is intended to make use of the counter’s internal prescaler. But by employing a 10-MHz precision frequency generator as an external clock, [SM6VFZ] found that inputs up to a bit above 151 MHz ended up countable with 1-Hz precision. Earlier mentioned that place, factors started to drift, but that’s nevertheless rather wonderful performance from some thing cobbled collectively on an eval board in a decidedly suboptimal way.

We’d think about this outcome could lead to some interesting initiatives, considering the fact that the undocumented limit for this timer places it very well in just vary of numerous beginner radio allocations. Even if it doesn’t demonstrate handy, which is Okay — just looking at how considerably issues can be pushed is amazing also. And it’s not like this is the 1st time we’ve caught [SM6VFZ] persuading an ATtiny to do unusual points, either.