Patent ID: 7479908
Filing Date: 2009-01-20
Classification: H03M

Abstract:
1. A semiconductor device comprising: an A/D converter; a digital processing circuit for performing processing based on conversion results from the A/D converter; and a test circuit for checking a differential nonlinearity error (DNLE) of the conversion results from the A/D converter, wherein the test circuit includes: a storage circuit for storing occurrence repetition for respective digital output values that are the conversion results obtained by the AID converter by making conversions for a predetermined period of time or for a certain number of outputs, and a test output terminal for externally outputting data on the occurrence repetition stored in the storage circuit; and the test circuit externally outputs the occurrence repetition data stored in the storage circuit, after the conversions made by the A/D converter for the predetermined period of time or for the certain number of outputs are completed.