I just want to post here our finding regarding the GPOI2 and ATTACH function this pin can be assigned to.
It seems that when GPIO2 pin is assigned the ATTACH function to, it can sink only 50uA!
It means the pull up resistor must be much higher than 10k (value usually used here and in the Eval Board as well).
If 10k is used, the GPIO2 will not be able to pull the line below ~1,2V, when the Sink is attached.
On the picture below you can see this behavior:
GPIO1: configured to ATTACH_FLT_ALT, pull-up = 10k, pulls the line to 0V
GPIO2: configured to ATTACH, pull-up = 10k, line stays at ~1.2V
All measurements were taken on the EVQ4242B-VE-00A, firstly with initial HW configuration, and afterwards with configuration where C7/R7 were removed.
Our FAE has been already informed regarding this “feature”, but we haven’t received any feedback or confirmation for now, why this is the case and if this can be reproduced from the MPS’s side.
Please can you check this on your side or we have a mistake on our side?
yes, I had placed 100k before I posted here, and it was working, of course.
With this post I just wanted to confirm with MPS if this is a specific desing “feature” for the chip itself, since it hasn’t been clearly documented, niether in Datasheet nor in Eval Board.
Also, it was confusing why the function POL on the GPIO2 works fine with 10k pull up, however the function ATTACH not.
Moreover, this “feature” is specific for both silicium revisions, MPQ4242 and MPQ4242B.
please could you tell me if you have found out, why there is an issue with GPIO2 and 10k pullup if it is configured to ATTACH function?
Also the confusing thing here is the power sharing function depicted on the Figure 14 where also 10k resistors were used.
I am wondering how this has worked, if we had experienced the issus with 10k on GPIO2 when it is configured to ATTACH fuinction.
