CRLC663: general purpose output functionality

[jof]

Hi,

We would like to make use of the additional general purpose outputs of the CRLC663 chip in a future project to save pins on a MCU.  We would like to use the Pins OUT0 to OUT3 which are usually for the boundary scan.

I've not found any information about the hardware functionality of the pins in the datasheet. The critical informations would be if the pins are either "voltage out" (like a MCU) or "sink" (eg. open drain) and how much current can be used per pin and in common. I know that some devices can provide like 5mA per port, but for example only 15mA in sum of all pins.

We aim to use 4 LED's which have 1-3mA per LED.

Also it would be interesting how the outputs react when the device is in reset or sleep mode.

Thank you for any information.

[weidong_sun]

Hello Jonathan ,

     OUT0~OUT7 all can be used as GPIO function. But these pins are multiplexed. You should do 2 steps for GPIO:

1. Enable them on corresponding bit in Register "PinEn"

[note]

     You can try to write 1 at bit0, and check if GPO function is enabled, otherwise write 0, please! I also didn't find detailed description on 1 or 0 for GPO function.

2. Output High Or Low  in Register "8.15.2 PinOut"

Write 1 on related bit, High level should be output, otherwise Low level.

In addtion, if your LED needs 1-3mA,  it is no problem to driver them diretly via GPO.  if higher current is needed, you can add a MOSFET to driver LEDs.

Have a nice day!

Best Regards,

Weidong Sun