Abstract: A device including a controller coupled to memory components via a forward data path, and a signature register coupled to the memory components via a backward data path. The controller provides memory address signals and a controller clock signal to the memory components via the forward data path, which includes first circuitry to provide test-enable signals to the memory components that enable the memory components to read stored memory values. The backward data path includes second circuitry to receive from the memory components a set of memory signals and combine them into a combined signal. Each memory signal is associated with a respective one of the memory components and includes at least one stored memory value read from the corresponding memory component. The signature register calculates a test signature based on the combined signal and compares the test signature to an expected signature.

Abstract: An integrated circuit. The integrated circuit includes: (i) a clocked circuit operable in response to a clock; (ii) a clock providing circuit, coupled to clock the clocked circuit at a selectable frequency; (iii) a test circuit coupled to the clock providing circuit and the clocked circuit; and (iv) a pad configured to receive an external signal, wherein the selectable frequency is selected in response to the external signal.

Abstract: An apparatus includes a controller adapted to be coupled to memory components in parallel and configured to provide memory address signals and a controller clock signal to the memory components, a memory enable logic circuit coupled to the controller and adapted to be coupled to the memory components in parallel and configured to provide test-enable signals to the memory components. The test-enable signals enable, with the controller clock signal, the memory components to read locally stored memory values. The apparatus includes a multiplexer adapted to be coupled to the memory components in parallel and configured to receive from the memory components memory signals that include the memory values in respective sequences of the memory clock signals, and a pipeline coupled to the multiplexer and the controller and configured to receive the memory values from the multiplexer and send the memory values to a multiple input signature register of the controller.

Abstract: An apparatus includes a first group of memory units and a second group of memory units coupled to a first data path and a second data path coupled to a controller, a first delay element on the first data path coupled to the second group of memory units and configured to send, from the controller to the second group of memory units, signals for write and read operations in a sequence of time cycles delayed by a time cycle with respect to the first group of memory units, and a second delay element on the second data path and coupled to the first group of memory units and configured to send, from the first group of memory units to the controller, test result signals delayed by a time cycle, the delayed test result signals having a matching delay to the delayed write and read operations.

Abstract: An apparatus includes a first group of memory units and a second group of memory units coupled to a first data path and a second data path coupled to a controller, a first delay element on the first data path coupled to the second group of memory units and configured to send, from the controller to the second group of memory units, signals for write and read operations in a sequence of time cycles delayed by a time cycle with respect to the first group of memory units, and a second delay element on the second data path and coupled to the first group of memory units and configured to send, from the first group of memory units to the controller, test result signals delayed by a time cycle, the delayed test result signals having a matching delay to the delayed write and read operations.

Abstract: An apparatus includes a controller adapted to be coupled to memory components in parallel and configured to provide memory address signals and a controller clock signal to the memory components, a memory enable logic circuit coupled to the controller and adapted to be coupled to the memory components in parallel and configured to provide test-enable signals to the memory components. The test-enable signals enable, with the controller clock signal, the memory components to read locally stored memory values. The apparatus includes a multiplexer adapted to be coupled to the memory components in parallel and configured to receive from the memory components memory signals that include the memory values in respective sequences of the memory clock signals, and a pipeline coupled to the multiplexer and the controller and configured to receive the memory values from the multiplexer and send the memory values to a multiple input signature register of the controller.

Abstract: An integrated circuit. The integrated circuit includes: (i) a clocked circuit operable in response to a clock; (ii) a clock providing circuit, coupled to clock the clocked circuit at a selectable frequency; (iii) a test circuit coupled to the clock providing circuit and the clocked circuit; and (iv) a pad configured to receive an external signal, wherein the selectable frequency is selected in response to the external signal.