We are planning to use the ADP5585 keypad controller in our design but I could not find any data as to the default settings of the registers. Does anyone have this information?
Our main concern has to do with the RESET block, since we want to use the feature to reset our MCU, but we need to know the default state of the RESET block register on power up.
We plan on using pin C4 (for RESET2) and our reset signal is ACTIVE LOW. We need to know what state the C4 pin is when we POR the controller. If the default state is LOW then the controller will hold our MCU in reset constantly.
Any assistance will be appreciated.
The ADP5585 comes in a few different flavors with respect to the initial state of the GPIOs. On page 8 of the ADP5585 datasheet Rev. A, there is a listing of the different options.
If using the WLCSP, option ADP5585ACBZ-02-R7 will allow you to have the C4 pin floating on start-up. You could then have an external pull down resistor (I recommend around 300 kΩ).
If you are planning on using the LFCSP version of the ADP5585, you could put a strong pull-down resistor external to the chip on pin C4. There is a 300 kΩ pull-up on C4 on start up of the ADP5585 LFCSP versions.