| 摘要 |
A method and apparatus for time-division demultiplexing and decompressing a compressed input stimulus 421, provided at a selected data-rate R1 421, into a decompressed stimulus 424, 426, 433, 435, driven at a selected data-rate R2 442, for driving selected scan chains in a scan-based integrated circuit 401. The scan-based integrated circuit 401 contains a high-speed clock CK1 443, a low-speed clock CK2 442, and a plurality of scan chains 411, . . . , 418, each scan chain comprising multiple scan cells coupled in series. The method and apparatus comprises using a plurality of time-division demultiplexors (TDDMs) 402, 403 and time-division multiplexors (TDMs) 408, 409 for shifting stimuli 421 and test responses 444 in and out of high-speed I/O pads. When applied to the scan-based integrated circuit 401 embedded with one or more pairs of decompressors 404, 405 and compressors 406, 407, it can further reduce the circuit's test time, test cost, and scan pin count. A synthesis method is also proposed for synthesizing the time-division demultiplexors (TDDMs) 402, 403, decompressors 404, 405, compressors 406, 407, and time-division multiplexors (TDMs) 408, 409.
|
