Enabling multiple testing devices

1. A method comprising:

determining whether a first external testing device is coupled to a system;

provided said first external testing device is coupled to said system, enabling said first external testing device to operate with an interface of said system capable of coupling to a device under test; and

provided said first external testing device is not coupled to said system, enabling a second external testing device to operate with said interface of said system capable of coupling to said device under test.

2. The method as described in claim 1 wherein said determining comprises receiving a signal that is generated when said first external testing device is coupled to said system.

3. The method as described in claim 1 wherein said determining comprises utilizing a multiplexer.

4. The method as described in claim 1 wherein said determining comprises utilizing a multiplexer coupled to receive a signal associated with said first external testing device being coupled to said system.

5. The method as described in claim 1 wherein said enabling said first external testing device to operate with said interface of said system comprises utilizing a first signal conditioning to enable signaling associated with said first external testing device.

6. The method as described in claim 5 wherein said enabling said second external testing device to operate with said interface of said system comprises utilizing a second signal conditioning to enable signaling associated with said second external testing device.

7. The method as described in claim 1 wherein said first external testing device comprises an In-Target Probe device or a boundary-scan device.

8. The method as described in claim 1 wherein said first external testing device comprises an In-Target Probe device and said second external testing device comprises a boundary-scan device.

9. The method as described in claim 1 wherein said device under test is a microprocessor or electrical circuitry that can be configured.

10. A system comprising:

means for ascertaining whether a first external testing device is coupled to a computer system;

means for capacitating said first external testing device to operate with an interface of said computer system capable of coupling to a device under test, provided said first external testing device is coupled to said computer system; and

means for capacitating a second external testing device to operate with said interface of said computer system, provided said first external testing device is not coupled to said computer system.

11. The system of claim 10 wherein said means for ascertaining involves receiving a particular voltage, electrical difference or electrical signal that identifies said first external testing device.

12. The system of claim 10 wherein said means for ascertaining comprises utilizing a multiplexer.

13. The system of claim 10 wherein said means for ascertaining comprises utilizing a multiplexer having a selector input coupled to receive a signal associated with said first external testing device being coupled to said computer system.

14. The system of claim 10 wherein said means for capacitating said first external testing device to operate with said interface of said computer system comprises supplying a first signal conditioning to enable signaling associated with said first external testing device.

15. The system of claim 14 wherein said means for capacitating said second external testing device to operate with said interface of said computer system comprises supplying a second signal conditioning to enable signaling associated with said second external testing device.

16. The system of claim 10 wherein said first external testing device comprises an In-Target Probe device or a boundary-scan device.

17. The system of claim 10 wherein said first external testing device comprises an In-Target Probe device and said second external testing device comprises a boundary-scan device.

18. The system of claim 10 wherein said device under test comprises a microprocessor.

19. A circuit comprising:

a multiplexer coupled to determine whether a first external testing device is coupled to a computer system; and

an enabler circuit coupled to said multiplexer, wherein said multiplexer for allowing said first external testing device to operate with an interface of said computer system capable of coupling to a device under test when said first external testing device is coupled to said computer system, said multiplexer also for allowing a second external testing device to operate with said interface of said compute system when said first external testing device is not coupled to said computer system.

20. The circuit of claim 19 wherein said multiplexer is coupled to receive a signal indicating said first external testing device is coupled to said computer system.

21. The circuit of claim 19 wherein said multiplexer is coupled to receive a signal indicating said second external testing device is coupled to said computer system.

22. The circuit of claim 19 wherein said enabler circuit for receiving input signals from said first external testing device or second external testing device.

23. The circuit of claim 19 wherein said multiplexer is coupled to receive input signals associated with said first external testing device or second external testing device from said enabler circuit.

24. The circuit of claim 19 wherein said multiplexer is coupled to output first external testing device signals or second external testing device signals.

25. The circuit of claim 19 wherein said first external testing device comprises an In-Target Probe device or a boundary-scan device.

26. The circuit of claim 19 wherein said first external testing device comprises an In-Target Probe device and said second external testing device comprises a boundary-scan device.

27. The circuit of claim 19 wherein said device under test is a microprocessor or electrical circuitry that can be configured.