Transaction redirection mechanism for handling late specification changes and design errors

Abstract

Redefined hardware structured transactions and the associated responses in a data processing device are made user programmable. Three registers, a identifier register, a mask register and a response register, are used to redirect transactions or other operations within an application specific integrated circuit after post-silicon testing has been completed and there is no opportunity to redirect the hardware logic contained therein. When enabled, the registers allow for the insertion of blank table entries that can be programmed at a later time to handle unexpected output responses which occur due to unforeseen problems in the preprogrammed operation of the device. Transaction redirection can be accomplished on selected fields of identified transactions. The method is applicable to any hardware device in which it is desired to redirect actions originally defined in look-up tables when such tables are not capable of adjustment or alteration without redesign or re-manufacture.