Test Compression / Decompression Based on JPEG VLC Algorithm

Test data compression /decompression schemes for testing SoCs can reduce test application cost. A drawback of the previous schemes, however, is that a decompressor must be embedded in an SoC under test. In this paper, we target the testing of SoCs with multimedia cores and introduce a scheme of test compression / decompression with the decoding function in the multimedia cores. This scheme can utilize the decoder and encoder in a multimedia core for compressing and decompressing test data, and consequently it requires slight hardware overhead. As an example of the proposed scheme, we focus on a lossless variable-length coding (VLC) in the JPEG algorithm, and propose a test compression / decompression method using the VLC decoder. We also propose a test generation method for this scheme. Experimental results show that the test compression with the VLC can achieve high compression ratio and the proposed test generation method can increase the compression ratio.