CPLD - Really, what is it and why is the recent update urgent?

Question

Dell just notified me that the R760 and R660 models at a minimum have an urgent need to update CPLD to version 1.2.7. Of course, I still have no concrete idea of what this technology does since Dell does not seem to provide much info. There is a post from 2011 asking what it is and another one from 2020 (‎CPLD in Dell PowerEdge servers | DELL Technologies) asking the same thing that does not articulate its functions.

On the Dell site (PowerEdge CPLD R760/660 Version 1.2.7 | Driver Details | Dell US) under "Fixes and Enhancements" the list "BOSS PG w/a"...so in addition to not understanding what CPLD does for us, there is no way to determine what it is supposed to fix which presumably is the only reason it should be marked as urgent.

Anyone know of a web page that actually provides helpful info so busy admins can review, and understand the update/risks before we move to rollout?

DELL-Charles R · Answer

Hello,

CPLD stands for Complex Programmable Logic Device. It is a hardware component on the system board that provides low-level control logic for critical server functions. Not all systems have a CPLD update. Unlike BIOS, which handles high-level initialization, CPLD manages board-level operations such as:

Power sequencing and fail-safe voltage monitoring
Reset logic for CPUs and other components
Coordination between system board devices beyond what BIOS can do

For PowerEdge R760/R660 CPLD v1.2.7, this update is marked Urgent because:

It contains critical bug fixes and improvements for system stability and reliability.
It may include security fixes and enhancements for compatibility with other firmware (BIOS, iDRAC, BOSS controller).
Dell strongly recommends applying this update as soon as possible to maintain system health and prevent potential failures during firmware or hardware changes
Update CPLD separately from other firmware (BIOS, iDRAC).

The only release note for this update is the notation on the download page:

Fixes & Enhancements

BOSS PG w/a

https://www.dell.com/support/home/en-us/drivers/DriversDetails?driverID=XJG0V

Meaning of “BOSS PG w/a”

BOSS = Boot Optimized Storage Solution (Dell’s dedicated RAID controller for boot drives).

PG = Power Good signal, which indicates stable power before components initialize.

w/a = Workaround or adjustment.

So, “BOSS PG w/a” refers to a workaround for Power Good signal handling for the BOSS controller, ensuring proper power sequencing and stability during system initialization. This prevents boot failures or RAID initialization issues when the BOSS card is present.

Summary Table:

Component	Role	Why Update?
CPLD	Board-level logic for power/reset	Fixes BOSS PG handling, improves stability, prevents POST hangs.

Systems Management General

CPLD - Really, what is it and why is the recent update urgent?

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