Abstract: An automated test system for a device under test (DUT) compresses the stimulus waveform before transferring it to a storage device or over a data transfer interface. The compressed stimulus waveform data are decompressed, and if required converted to analog form, then applied as a stimulus to the DUT. In response, the DUT produces a response waveform. The response waveform is compressed before transferring it to a storage device or over a data transfer interface. If the response waveform is analog, it is converted to digital before compression. The compressed waveform is decompressed for further analysis or display by a host computer. Features of the response waveform can be calculated from the compressed or uncompressed waveform data. Several configurations that include compression and decompression of stimulus and/or response waveforms in test systems are described.

Abstract: A compressor for waveforms having at least two waveform states separates the waveform samples into waveform state sample vectors for each waveform state. Waveform state encoders encode the waveform state sample vectors separately to provide compressed waveform data. The waveform state encoder selects waveform state pattern vector and associated codes to represent the waveform state sample vectors. The differences between samples of the waveform state sample vector and waveform state pattern vector are calculated and encoded. Encoding can be lossless or lossy. The waveform state pattern vectors and other parameters for compression are determined during a training period. The waveform state encoders detect features in the waveform state sample vectors and waveform state pattern vectors that are useful for common oscilloscope measurements. Typical waveform states include level states and edge states.

Abstract: A compressor for waveforms having at least two waveform states separates the waveform samples into waveform state sample vectors for each waveform state. Waveform state encoders encode the waveform state sample vectors separately to provide compressed waveform data. The waveform state encoder selects waveform state pattern vector and associated codes to represent the waveform state sample vectors. The differences between samples of the waveform state sample vector and waveform state pattern vector are calculated and encoded. Encoding can be lossless or lossy. The waveform state pattern vectors and other parameters for compression are determined during a training period. The waveform state encoders detect features in the waveform state sample vectors and waveform state pattern vectors that are useful for common oscilloscope measurements. Typical waveform states include level states and edge states.

Abstract: An enhancement that reduces the digital interface rate of analog-to-digital (A/D) and digital-to-analog (D/A) converters through the use of compression and decompression is described. Improved A/D converters compressing a sampled version of an A/D converter's analog input signal in real time, thereby significantly decreasing the required bit rate of the A/D converter's digital interface. Similarly, improved D/A converters decrease the required bit rate of the D/A converter's digital interface. D/A converters include a decompressor that decompresses the D/A converter's compressed digital input in real time, prior to conversion to an analog output signal.