Patent ID: 6920416

Claim:
An electronic system comprising: an application system including electronic circuitry to be tested, serial scan shift register latches included within said electronic circuitry, an internal serial scan generator embedded in the application system upon manufacture and connected to said serial scan shift register latches of said electronic circuitry thereby facilitating testing of said electronic circuitry, said internal serial scan generator having a disable line for disabling said internal serial scan generator, a set of terminals adapted for connection of an cable to said application system, said set of terminals including a disable terminal connected to said disable line and an external serial input connected to said input of said serial scan shift register latches for optional connection of an external serial scan register to thereby facilitate testing of said electronic circuitry; an external emulation system including a cable adapted for connection to said set of terminals, a detachable external serial scan generator detachably connectable to said serial scan shift registers of said electronic circuitry via said external serial input, said set of terminals and said cable thereby facilitating testing of said electronic circuitry; and wherein connection of said cable to said set of terminals disables said internal serial scan generator via said disable line.