P1022 GPDAT: What is the best way to account for output only pins returning zero exception?

[adamgarrison]

Referring to 23.4.4 of the P1022 TRM.  Why do the output only GPOs always return zero while the GPIOs configured as outputs return actual data?  This seems silly.  Is there a workaround?

Thank you,

Adam

[CommunityBot · Accepted solution]

This an automatic process.

We are marking this post as solved, due to the either low activity or any reply marked as correct.

If you have additional questions, please create a new post and reference to this closed post.

NXP Community!

[alexander_yakov]

Looking to Figure 23-1 in the same section, I see the loopback circuit allowing reading the actual state of the external pin is the only difference between GPIO pin and output-only pin. So I do not see anything incorrect it the fact that output-only pin can not act as input, it simply does not have this input circuit.

[adamgarrison]

Alexander,

Thank you for the referral to the figure.  This explains why the exception occurs.  Is there a suggested work around beyond a memory register used to shadow the output pin state?

Thanks,

Adam