Systems and methods for providing output data in an LBIST system having a limited number of output ports

A method implemented in a device which incorporates circuitry for logic testing comprising:

• performing one or more test loops, wherein each test loop includes
• receiving input data for testing through a first number of shared input/output (I/O) ports,
• performing testing on functional logic within the device using the input data and thereby generating test data, wherein the test data comprises a number of bits greater than the first number, and
• outputting the test data through the shared I/O ports in a plurality of successive segments, wherein each segment comprises a portion of the test data.

A system comprising,

• test circuitry coupled to target logic under test,
• wherein the test circuitry is configured to perform logic tests on the target logic using input data and thereby generate signature data;
• a first number of shared I/O ports coupled to the test circuitry and configured to alternately convey the input data to the test circuitry and output the signature data generated by the test circuitry;
• wherein the signature data comprises a second number of bits greater than the first number of shared I/O ports;
• and
• wherein the test circuitry is configured to successively output multiple segments of the signature data through the shared I/O ports, wherein each segment has a third number of bits no greater than the first number of shared I/O ports.