请参考这个文档：
http://www.cisco.com/c/en/us/td/docs/switches/datacenter/sw/best_practices/cli_mgmt_guide/cli_mgmt_bp/epld_upgrade.htmlan electronic programmable logic device (EPLD).
EPLDs are hardware components such as ASICs on I/O modules that can be upgraded without having to replace the hardware. EPLD upgrades are typically not required, but in some cases, such as new chassis installs or chassis redeployments, we recommend that you upgrade to the latest EPLD version to ensure that all upgradable hardware components have the latest feature enhancements and caveat fixes.
注意： Cisco NX-OS software can be upgraded without upgrading to the latest EPLD image. Customers should review the EPLD release notes on cisco.com and determine if they need to upgrade their EPLDs based on new features or caveat fixes.
n7000# show install all impact epld bootflash:n7000-s1-epld.5.1.1.img //查看i/o模块是否可以升级以及带来的影响。
n7000# install module 1 epld bootflash:n7000-s1-epld.5.1.1.img //升级epld
除非有特殊的要求， epld是可以不升级的。。。
thanks, martin
