Sambanova Systems, Inc.

Dinesh Rajasavari Amirtharaj

Thomas Alan Ziaja

Uma E Durairajan

An integrated circuit (IC) includes first and scan latches that are enabled to load data during a first part of a clock period. A clocking circuit outputs latch clocks with one latch clock driven to an active state during a second part of the clock period dependent on a first address input. A set of storage elements have inputs coupled to the output of the first scan latch and are respectively coupled to a latch clock to load data during a time that their respective latch clock is in an active state. A selector circuit is coupled to outputs of the first set of storage elements and outputs a value from one output based on a second address input. The second scan latch then loads data from the selector's output during the first part of the input clock period.

Single 'A' latch with an array of “B” latches

A processor unit includes a memory and an ALU coupled with the memory. The processor unit also comprises a test controller, a test control register, and a signature register. The test controller manages a series of steps to test the processor unit. It overrides an ALU control signal with a replacement ALU control signal, stored in the test control register. It generates a test pattern and writes it to a memory address. It reads memory output data from the memory address, and forwards it to the ALU. The ALU executes an operation on the memory output data based on the replacement ALU control signal. The ALU output provides a test result, which is compressed to obtain a test signature, and stored in the signature register.

Built-in self-test for processor unit with combined memory and logic

Testability of memory on integrated circuits is improved by connecting storage elements like latches in memory to scan chains and configuring memory for scan dump. The use of latches and similar compact storage elements to form scannable memory can extend the testability of high-density memory circuits on complex integrated circuits operable at high clock speeds. A scannable memory architecture includes an input buffer with active low buffer latches, and an array of active high storage latches, operated in coordination to enable incorporation of the memory into scan chains for ATPG/TT and scan dump testing modes.

Method and circuit for row scannable latch array

Method and circuit for scan dump of latch array

An IC includes an array of processor units, arranged in two or more subarrays. A subarray has a test generator, a multiplexer to apply a test vector to a datapath, and a test result output. It includes one or more processor units. A test result compressor is coupled with an output of the datapath, and compresses output data to obtain a test signature, which it stores in a signature register. The signature register is legible from outside the subarray. The datapath includes one or more memories and one or more ALUs. Test data travels through the full datapath, including the memories and the ALUs. ALU control registers are overridden during test to ensure a testable datapath.

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Milpitas, CA, United States of America

Dinesh Rajasavari Amirtharaj