Abstract: An integrated circuit has a Built-In Self-Test (BIST) controller (10) that has a sequencer (16) that provides test algorithm information for multiple memories (44, 46, 48, 50). The sequencer identifies the test algorithm that is to be performed and multiple memory interfaces (32, 34, 36, 38) interpret the output of the sequencer and perform the algorithm on the multiple memories. The multiple memories may be different or the same regarding type, size, data widths, etc. Having multiple memory interfaces provides flexibility to tailor the test algorithm for each memory, but yet keeps the advantage of a single source of identifying the test algorithm. With the memories being non-volatile, timing information with regard to the test algorithm is stored in the memories. This timing information is read prior to performing the test algorithm and is used in performing the test algorithm.

Abstract: An integrated circuit has a Built-In Self-Test (BIST) controller (10) that has a sequencer (16) that provides test algorithm information for multiple memories (44, 46, 48, 50). The sequencer identifies the test algorithm that is to be performed and multiple memory interfaces (32, 34, 36, 38) interpret the output of the sequencer and perform the algorithm on the multiple memories. The multiple memories may be different or the same regarding type, size, data widths, etc. Having multiple memory interfaces provides flexibility to tailor the test algorithm for each memory, but yet keeps the advantage of a single source of identifying the test algorithm. With the memories being non-volatile, timing information with regard to the test algorithm is stored in the memories. This timing information is read prior to performing the test algorithm and is used in performing the test algorithm.

Abstract: An integrated circuit has a Built-In Self-Test (BIST) controller (10) that has a sequencer (16) that provides test algorithm information for multiple memories (44, 46, 48, 50). The sequencer identifies the test algorithm that is to be performed and muliple memory interfaces (32, 34, 36, 38) interpret the output of the sequencer and perform the algorithm on the multiple memories. The multiple memories may be different or the same regarding type, size, data widths, etc. Having multiple memory interfaces allows for flexibility in allowing for tailoring the test algorithm for each memory but yet keeping the advantage of a single source of identifying the test algorithm. The BIST uses a method to permit the external control for the repetition of test algorithms for multiple memories over different operating conditions, such as different voltages and temperatures.

Abstract: An integrated circuit has a Built-In Self-Test (BIST) controller (10) that has a sequencer (16) that provides test algorithm information for multiple memories (44, 46, 48, 50). The sequencer identifies the test algorithm that is to be performed and multiple memory interfaces (32, 34, 36, 38) interpret the output of the sequencer and perform the algorithm on the multiple memories. The multiple memories may be different or the same regarding type, size, data widths, etc. Having multiple memory interfaces provides flexibility to tailor the test algorithm for each memory, but yet keeps the advantage of a single source of identifying the test algorithm. With the memories being non-volatile, timing information with regard to the test algorithm is stored in the memories. When test algorithms fail or complete execution, pertinent BIST information is stored in non-user addressable space of the multiple memories.

Abstract: Built-In-Logic-Block-Observation registers BILBO are coupled to the output of a Control-Read-Only-Memory CROM in the write-state-machine of a flash EPROM. The Built-In-Logic-Block-Observation registers BILBO include master/slave latches M/SL, shadow latches SHL, and other logic circuitry that enable the various modes of operation required for pulse timing and for signature analysis. During operation a pre-defined FLASH command sequence requests a Control-Read-Only-Memory CROM signature analysis that executes a set of instructions causing the Built-In-Logic-Block-Observation registers BILBO to be placed in the Multiple-Input-Signature-Register Mode and that steps through the Control-Read-Only-Memory CROM until all valid addresses have been evaluated. The resultant Control-Read-Only-Memory CROM signature is then scanned out and verified. The invention eliminates the need for a separate stand-alone Linear-Feedback-Shift-Register LFSR used for pulse timing.

Abstract: A process for forming a topside substrate contact in a trenched semiconductor structure. A trench (24, 26) is etched into a P- block of substrate (10) material. The trench (24, 26) is filled with silicon dioxide, and then the substrate material (10) circumscribed by the trench (24, 26) is removed to form a well. A subcollector (48) is implanted in the well of the P. substrate. Epi material (50) is grown in the well to the top of the silicon dioxide-filled trench. A device (59) is formed in the epi (50). Ohmic contacts (70) are formed on the topside of the substrate to the device (59) within the well, and to the P- substrate itself outside the trench.