US Patent 7315971 Systems and methods for improved memory scan testability

A method and system for testing a device that includes both a digital and analog portion. The digital portion includes a plurality of latch devices, and the analog portion includes a plurality of memory cells and a plurality of selector devices. A selector input controls each of the plurality of selector devices, which is electrically coupled to a respective one of the memory cells, and is indirectly coupled to one of the plurality of latch devices. A load clock loads a pattern into the plurality of latch devices. A derivative of the pattern is received by the plurality of selectors and returned to the plurality of latch devices with the assertion of the selector input. A system clock loads the derivative of the pattern into the plurality of latch devices.