Link equalization tester

1. A physical layer test and measurement system with protocol awareness, comprising:

an analog front end (AFE) unit with physical layer testing capabilities, the AFE unit adapted to generate and provide a signal to a device under test, the device under test acting as a signal receiver, the AFE unit further adapted to receive a signal from the device under test, the device under test acting as a signal transmitter; and

a general purpose platform (GPP) with protocol awareness capabilities of one or more predefined protocols, the GPP further being adapted to perform testing on an input signal received from the AFE to determine errors on a protocol packet level at a plurality of different speeds of operation of the device under test in accordance with one or more of the one or more predefined protocols in accordance with the steps of:

(a) selecting a first of a plurality of preset values;

(b) sending an equalization signal from the AFE to the device under test;

(c) requesting a change in transmitter equalization to the device under test to a predetermined setting;

(d) confirming a change in transmitter equalization by the device under test to the predetermined setting within a predetermined time;

(e) entering the system into a loopback mode;

(f) sending a compliance pattern to the device under test from the AFE;

(g) capturing a waveform output from the device under test;

(h) repeating steps b-g for each of the plurality of preset values.

2. The system of claim 1 , wherein the determination of errors on a protocol packet layer at a plurality of different speeds comprise performing a link equalization testing sequence.

3. The system of claim 1 , further comprising a counter for counting a number of protocol packets including an error corresponding to one or more of the one or more predefined protocols.

4. The system of claim 3 , further comprising a calculator for calculating a bit error rate in accordance with the counted number of protocol packets including an error.

5. A method for performing link equalization testing, comprising the steps of:

(a) providing a protocol aware test apparatus;

(b) selecting a first of a plurality of preset values;

(c) sending an equalization signal from the protocol aware test apparatus to a device under test;

(d) requesting a change in transmitter equalization setting to the device under test to a predetermined setting by the protocol aware test apparatus;

(e) confirming a change in transmitter equalization setting by the device under test to the predetermined setting within a predetermined time;

(f) entering the device under test into a loopback mode;

(g) sending a compliance pattern to the device under test from the protocol aware test apparatus;

(h) capturing a waveform output from the device under test;

(i) repeating steps b-h for each of the plurality of preset values; and

(j) analyzing the captured waveforms output from the device under test in response to each of the plurality of preset values.

6. The method of claim 5 , wherein the protocol aware test apparatus is aware of a PCI Express Gen 3 protocol.

7. The method of claim 6 , wherein a speed of communication is first requested to be changed to 8G.

8. The method of claim 5 , further comprising the step of determining a fastest speed available for a particular device under test resulting in a desired eye pattern.

9. The method of claim 8 , wherein the fastest speed available is therefore a speed at which the device under test is rated in accordance with a PCI Express Gen 3 protocol.

10. The method of claim 8 , further comprising the step of, after sending an equalization signal from the protocol aware test apparatus to the device under test, responding electrically and protocol-wise within 500 ns to the transmission equalization setting request received from the device under test.

11. A physical layer test and measurement system, comprising:

a protocol aware test apparatus for transmitting testing data;

a device under test for receiving the transmitted testing data; and

an oscilloscope for receiving an output waveform from the device under test;

wherein the protocol aware test apparatus selects a first of a plurality of preset values, sends an equalization signal from the protocol aware test apparatus to the device under test, requests a change in transmitter equalization to the device under test to a predetermined setting, confirms whether the device under test changes to the predetermined setting within a predetermined time, and sends a compliance pattern to the device under test after placing the device under test in a loopback mode; and

wherein a waveform output from the device under test is captured by the oscilloscope.

12. The physical layer test and measurement system of claim 11 , wherein the process of the protocol aware test apparatus and oscilloscope are repeated for each of the plurality of preset values.

13. The physical layer test and measurement system of claim 12 , wherein the captured waveforms output from the device under test in response to each of the plurality of preset values are analyzed to determine a response profile of the device under test.

14. The physical layer test and measurement system of claim 11 , wherein the protocol aware test apparatus is aware of a PCI Express Gen 3 protocol.

15. The physical layer test and measurement system of claim 14 , wherein changes in the speed of communication is performed in order to perform a link equalization testing sequence in order to provide a desired eye pattern.

16. The physical layer test and measurement system of claim 11 , wherein the protocol aware test apparatus is calibrated for jitter.

17. The physical layer test and measurement system of claim 11 , wherein the device under test is a system.

18. The physical layer test and measurement system of claim 11 , wherein the device under test is an Add In Card.

19. The physical layer test and measurement system of claim 18 , further comprising a riser card for receiving the Add In Card.

20. The physical layer test and measurement system of claim 11 , wherein the protocol aware test apparatus, after sending an equalization signal to the device under test, responds electrically and protocol-wise within 500 ns to the transmission equalization setting request received from the device under test.