Forum Discussion
Occasional ContributorAgilex 5 PWRMGT IO pin connections
If I am not using the PMBus Power Management function can I leave the following pins unconnected :-
PWRMGT_SCL, PWRMGT_SDA, PWRMGT_ALERT
Also what about the CvP_CONFDONE pin if we are only ever going to us AS configuration ?
7 Replies
SDavi9I would also like to ask about AS_nCS03 can we leave it floating since we are using only a single QSPI device ?
JohnT_AlteraRegular Contributor
Hi,
May I know which device part are you using? If you are using smartVID part then this need to be connected.
- JohnT_Altera
Are you using CVP?
- SDavi9
We will be using one of the following devices : A5EC008BM16AI4S, A5EC013BM16AI4S or A5EC028BM16AI4S - and we will not be using smartVID ! For the CvP_CONFDONE I found a note in the Quartus software when defining the options for the "Configuration Pin Options" that if not used then "can be used as a user I/O" thus I assume it CAN BE left N/C. I couldn't find this info in the Intel Docs - which is a shame !
I still need to know about AS_nCSO3 pin, PWRMGT_SCL & PWRMGT_ALERT/SDA(this is a shared pin with SDM_IO12).
- JohnT_Altera
Hi,
AS_nCSO3 pin, PWRMGT_SCL & PWRMGT_ALERT/SDA pin can be left floating if it is unused.
- SDavi9
Where is this documented ?
FakhrulA_alteraHi SDavi9,
As mentioned in above reply, AS_nCSO3, PWRMGT_SCL, PWRMGT_SDA, PWRMGT_ALERT, and CvP_CONFDONE are all safe to leave unconnected when their corresponding features are not used, per the SDM_IO unused‑pin rules.
• CvP_CONFDONE – Listed as an optional SDM signal in Table 14 – SDM Optional Signal Pins, and optional signals only require connection when used. Unused SDM_IO pins default to weak pull resistors and may remain N/C. (Document pp. 33–37) Pin Connection Guidelines Agilex™ 5 FPGAs and SoCs
• AS_nCSO3 – Part of AS x4. The AS×4 “Unused Configuration Pins” table shows unused SDM_IO pins (including SDM_IO8 / AS_nCSO3) can be left unconnected. (Document pp. 44–45) Device Configuration User Guide: Agilex™ 5 FPGAs and SoCs
• PWRMGT_SCL / PWRMGT_SDA / PWRMGT_ALERT – These SmartVID/PMBus signals are optional in Table 14 – SDM Optional Signal Pins. If SmartVID is not used, these pins do not require connection and may float. (Document pp. 33–37) Pin Connection Guidelines Agilex™ 5 FPGAs and SoCs
The SDM_IO pins follow a global rule documented in the “Unused Configuration Pins” in the document.This applies to all optional SDM signals unless explicitly stated otherwise (e.g., MSEL pins, nCONFIG, nSTATUS).
Regards,
Fakhrul
