The Cisco Nexus 9000
Series ACI-mode switches contain several programmable logical devices (PLDs)
that provide hardware functionalities in all modules. Cisco provides electronic
programmable logic device (EPLD) image upgrades to enhance hardware
functionality or to resolve known issues. PLDs include electronic programmable
logic devices (EPLDs), field programmable gate arrays (FPGAs), and complex
programmable logic devices (CPLDs), but they do not include ASICs. In this
document, the term EPLD is used for FPGA and CPLDs.
The advantage of
having EPLDs for some module functions is that when you need to upgrade those
functions, you just upgrade their software images instead of replacing their
EPLD image upgrades
for an I/O module disrupt the traffic going through the module because the
module must power down briefly during the upgrade. The system performs EPLD
upgrades on one module at a time, so at any one time the upgrade disrupts only
the traffic going through one module.
Cisco provides the
latest EPLD images with each release. Typically, these images are the same as
provided in earlier releases but occasionally some of these images are updated.
These EPLD image updates are not mandatory unless otherwise specified. The EPLD
image upgrades are independent from the Cisco ACI In Service Software Upgrade
(ISSU) process, which upgrades the system and kickstart images with no impact
on the network environment.
When Cisco makes an
EPLD image upgrade available, these release notes announce their availability,
and you can download them from