2026-01-12 9:29 AM
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
2026-01-12 9:42 AM - edited 2026-01-12 10:10 AM
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.
2026-01-12 10:35 AM - edited 2026-01-12 10:39 AM
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
2026-01-12 11:38 AM
Hi,
from ds L4Rx : ...same pin/functions
...and _l in table:
Needs correction in the ds L4P5 , i suppose.
2026-01-12 11:46 AM
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