JACK_INSERT and HOLD underlying issues

[Werner Almesberger]

Andy Green wrote:
> anything with HOLD we must have MICBIAS powered.  Even then maybe we
> don't make enough high level to detect a logic '1' at CPU interrupt
> input considering the load of the Mic.

Hmm, 3.3V/(2.2+.9)*.9 = 0.96V into a pin with Vil(max) = 0.8V and
Vih(min) = 2V looks more like an all-time low :-(

The circuit is almost identical to GTA01. I wonder how well we're
doing there. I don't remember any major complaints about HOLD, but
then, perhaps nobody tried ?

- Werner