Werner Almesberger 提到:
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
For HOLD function, we must have MICBIAS powered. In GTA01, we don't has
any pull high resistor in IO_3V3.
Because the HOLD function just for holds the phone or take a phone and
we don't use it to wake up CPU.
Best Wishes
Allen Chang
