Granted Patent B2

US 8,536,908 · App. 13/249,069 · Granted Sep 17, 2013

Abstract

Claims (29)

1. An apparatus for testing, comprising:

an integrated circuit having at least an output pin, wherein the integrated circuit includes:

a comparison circuit that is arranged to trip based on a power supply signal reaching a trip point;

an analog-to-digital converter that is arranged to convert the power supply signal into a digital signal having a power supply value that is based on a voltage associated with the power supply signal;

a storage component that is arranged to store the power supply value, and further arranged to provide the power supply value at the output pin; and

a latch circuit that is coupled between the analog-to-digital converter and the storage component, wherein the latch is arranged to open when the comparison circuit trips, such that, when the comparison circuit trips, the storage component continues to store the digital value such that the digital value corresponds to the voltage associated with the power supply signal when the comparison circuit tripped.

2. The apparatus of claim 1 , wherein the comparison circuit is further arranged to provide another trip point when the power supply signal reaches a low trip point that is less than the trip point, and wherein the analog-to-digital converter is arranged to be enabled when the power supply signal reaches the low trip point.

3. The apparatus of claim 1 , wherein the integrated circuit further includes a flash memory.

4. The apparatus of claim 1 , wherein the storage component includes a synchronous random access memory.

5. The apparatus of claim 1 , wherein the output pin includes a plurality of input/output pins.

6. The apparatus of claim 1 , wherein the storage component is arranged to enter a data-access mode upon receiving a command to enter the data access mode at the output pin, and wherein the storage component is configured to provide the digital value at the output pin when the storage component is in the data-access mode.

7. The apparatus of claim 1 , wherein

the analog-to-digital converter includes:

a resistor divider, chain having a plurality of tap points;

a plurality of comparators, wherein each comparator of the plurality of comparator has a first input that is coupled to a reference node, and a second input that is coupled to a corresponding one of the plurality of tap points of the resistor divider chain.

8. The apparatus of claim 7 , wherein

each comparator of the plurality of comparators has an output; and

wherein the latch circuit includes a plurality of latches, wherein each latch of the plurality of latches is coupled to a corresponding output of a corresponding comparator of the plurality of comparators.

9. A method for testing, comprising:

receiving a power-on reset signal that trips based on a power supply signal reaching a trip point;

performing an analog-to-digital conversion to convert the power supply signal into a digital signal having a power supply value that is based on a voltage associated with the power supply signal;

storing the power supply value;

providing the power supply value at the output pin of an integrated circuit; and

latching the digital signal when the power-on reset signal latches such that the digital value is stored such that, after the digital signal is latched, the digital value corresponds to the voltage associated with the power supply signal when the power-on reset signal tripped.

10. The method of claim 9 , further comprising:

providing another trip point when the power supply signal reaches a low trip point that is less than the trip point, wherein the analog-to-digital conversion is arranged to be enabled when the power supply signal reaches the low trip point.

11. The method of claim 9 , further comprising:

upon receiving a command to enter the data access mode at the output pin, entering a data access mode and;

while in the data access mode, providing the digital value at the output pin.

Assignments (6)