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AR# 20100

CPLD CoolRunner-II - Can Vccaux be disconnected or grounded to save power?


Can I disconnect or ground the Vaux pin to save power on a CoolRunner-II CPLD?


No, the Vaux pin cannot be disconnected or grounded to save power on a CoolRunner-II CPLD.

Vaux powers the JTAG I/O buffers, and floating or grounding this pin will result in unknown values being passed from these buffers to the core of the CPLD. This action can result in unexpected behavior in the JTAG state machine that can lead to a functional failure.

AR# 20100
Date Created 09/03/2007
Last Updated 12/15/2012
Status Active
Type General Article