Built-In Self Test Design of an Asynchronous Block Sorter

The design of an asynchronous block sorter and issues relating to its testability are discussed in this paper. The sorter takes an input data stream and sends it to the output sorted in descending order. The testable structure of the block sorter is implemented using the built-in self test (BIST) design methodology. A novel technique for changing the operation mode of the sorting cells of the block sorter which allows them to be set to normal operation mode or BIST mode sequentially or in parallel respectively is described. In BIST mode the sorting cells are tested in parallel reducing the overall test application time of the sorter. Fault simulation results reveal 100% testability of both single stuck-at-output faults at the high-level representation of the block sorter and all stuck-at faults inside data processing blocks of its sorting cells. The total area overhead of the BIST block sorter is 15.7%.