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Tool/software:
Hello all,
I would like to be able to read the state of GPIO2 when configured as input in GPIO mode (see below on why I need to).
I can do the same e.g. on a DS90UB948-Q1 by reading from Register 0x6E (Bit 2), but the data sheet of the DS90UB926Q-Q1 doesn't say anything about reading the current state.
Background:
I'm working on a test bench where the DS90UB926Q-Q1 is part of the unit under test. I need to read a (very slow) digital signal that is input to the DS90UB926Q-Q1 on GPIO2.
Usually, I would configure GPIO as back channel and measure the signal on the respective pin on the serializer. However, the DS90UB925Q-Q1 resides in a third-party-device (BasicCON4121 by Göpel) where I don't have access to that pin (the device was designed to always use the ROUT8 function of that pin).
On a similar Test bench, where a combination of DS90UB948-Q1 / DS90UB947-Q1 is used, I can just configure the pin as GPIO Input via Register 0x1e and read the current state of the pin via register 0x6e. However, for the DS90UB926Q-Q1, there is nothing mentioned in the data sheet.
Does anybody know if there is any way to accomplish that?
Thank you very much in advance!
Oliver Nittka
Hi Oliver,
The UB926 does not have the option to read the input state of the GPIO. I cannot confirm whether the GPI Pin status register was included in the UB926 so you can see if that works but it will be at your own discretion.
Best,
Jack
Hi Jack,
thank you very much for your answer!
I'm not sure I understand what you mean by "GPI Pin status register". I couldn't find anything in the datasheet or via google. Is there any common register description across the DS90UB-Series somewhere that I couldn't find? Or is this something different?
Thanks again!
Oliver
Hi Oliver,
The GPI Pin status register is register 0x6E. GPIO2 is bit 2. This register is shown in the 924 and 928 datasheet.
Best,
Jack
OK, now I understand, thanks a lot!
Unfortunately, the Bit doesn't seem to change when the Signal on GPIO2 changes.
A side note for future readers: I cannot be absolutely sure because I cannot measure within the UUT, but I have no reason to assume the UUT is defective, so the GPIO should toggle at some point, but Bit 2 in register 0x6e always stays 0.
Thanks agaein!
Oliver