System and method for enabling a vendor mode on an integrated circuit

1. A method of enabling a vendor mode in an integrated circuit, the method comprising the steps of:

(a) detecting a first potential applied at a no-connect pin of the integrated circuit;

(b) detecting a predetermined sequence of logical values applied at a set of pins of the integrated circuit; and

(c) generating a vendor mode enable signal using a logic gate to enable the vendor mode in the integrated circuit by vendor mode circuitry of the integrated circuit only if (a) and (b) are concurrent, wherein the no-connect pin does not connect with circuitry to the integrated circuit other than the logic gate.

2. The method of claim 1 wherein (c) comprises:

(c1) performing a logical AND operation to determine whether (a) and (b) are concurrent; and

(c2) activating the vendor mode circuitry in response to a logical TRUE result of the logical AND operation.

3. The method of claim 2 wherein (c1) comprises:

generating a first logical TRUE signal in response to (a);

receiving the first logical TRUE signal at a first input to a logic AND gate;

generating a second logical TRUE signal in response to (b); and

receiving the second logical TRUE signal at a second input to the logic AND gate.

4. The method of claim 1 wherein (a) comprises: measuring a variation from a clamping potential at the no-connect pin, wherein the clamping potential on the no-connect pin corresponds to inactivity of the vendor mode circuitry.

5. The method of claim 4 wherein the first potential corresponds to a logic value of one and the clamping potential corresponds to a logic value of zero.

6. The method of claim 1 further comprising:

disabling a user mode for the integrated circuit.

7. A method of enabling a vendor mode in an integrated circuit, wherein the integrated circuit includes a no-connect pin and a set of pins for activating vendor mode circuitry, using a logic gate, in response to a predetermined sequence of logical values on the set of pins, the method comprising the steps of:

applying a predetermined potential to the no-connect pin such that the no-connect pin does not connect with circuitry to the integrated circuit other than the logic gate;

concurrently applying the predetermined sequence of logical values to the set of pins; and

enabling the vendor mode in the integrated circuit by the vendor circuitry only when the predetermined potential on the no-connect pin and the predetermined sequence of logical values on the set of pins are concurrently applied.

8. The method of claim 7 wherein the potential corresponds to a logic value of one.