Patent ID: 8242800

Claim:
An apparatus in an integrated circuit for re-enabling the use of precluded extended JTAG operations, the apparatus comprising: a JTAG control chain, configured to enable/disable the extended JTAG operations; a feature fuse, configured to indicate whether the extended JTAG features are to be disabled; a level sensor, configured to monitor an external voltage signal, and configured to indicate that said external voltage signal is at a legal level; a machine specific register, configured to store a value therein; and an access controller, coupled to said feature fuse, said level sensor, said machine specific register, and said JTAG control chain, configured to determine that said feature fuse is blown, and configured to direct said JTAG control chain to enable the precluded extended JTAG operations if said external voltage signal is at said legal level and if said value matches an override value within said access controller during a period that said value is stored within said machine specific register.