What is _l in pin IO structure?

[waclawek.jan]

In the STM32L4P5xx datasheet, some pins' IO structure is labelled with _l (in combination with other letters). However, this letter is not explained in Table 14 nor anywhere else.

Can this please be explained?

Thanks,

JW

[Imen.D]

Hello @waclawek.jan 

Thank you for rising this up.

The pins' IO labelled with "_I" means the pin with LCD function supplied by VLCD supply.

I escalated this request (through internal ticket number 224978) to the relevant team to add this information in the impacted documentations.

[waclawek.jan]

Hi @Imen.D ,

The STM32L4P5xx does not have LCD controller (as in the segment-LCD controller - it does have LTDC, but those pins are normal CMOS outputs, not powered from a special power structure); and, relatedly, it does not have VLCD pin either.

Btw. I found VLCD references and also the _l suffix at various pins (even _l explained) in STM32L4R5xx, STM32L4R7xx and STM32L4R9xx datasheet (DS12023 Rev 5), too. Didn't check other L4+ models.

JW

[AScha.3]

Hi,

from ds L4Rx : ...same pin/functions

...and _l in table:

Needs correction in the ds L4P5 , i suppose.

[waclawek.jan]

As I've said, neither the 'L4Px nor 'L4Rx do have the LCD module, nor the VLCD pin.

IMO references to VLCD and the _l IO structure shour be removed from both datasheets (plus their crypto counterparts', if it's there too).

JW

[Imen.D · Accepted solution]

Hi @waclawek.jan 

Good catch. I agree with your remark: STM32L4+ Datasheets declare VLCD or "VLCD" GPIOs while LCD is not present.

We will take the necessary action to full review and correct the content of the impacted datasheets.