Abstract: The present application provides a circuit and method for testing a memory device. The memory device has multiple blocks addressable via a plurality of address lines and capable of inputting and/or outputting data via a plurality of data lines.

Abstract: A circuit and method for controlling internal test mode entry of an Asynchronous Static Random Access Memory (ASRAM) chip wherein the circuit includes an address code comparator for detecting whether address codes inputted via an address bus of the ASRAM chip match a predefined validation code; a test mode detector for determining whether to let the ASRAM chip enter into an internal test mode; a test mode clock generator for generating a clock signal for the test mode decoder; and a test mode decoder for generating a test control signal. The circuit of the present application uses the existing pins of the ASRAM chip to input a special section of codes to trigger the ASRAM to enter into its internal test mode, thereby reducing the difficulty of testing the products.

Abstract: The address transition detecting circuit includes two identical address transition detecting signal generating module, an inverter and a signal combining module. Both of the two address transition detecting signal generating modules have a unilateral delay circuit for generating an output pulse at the rising edge of the address signal and an output pulse at the falling edge of the address signal. The address transition detecting signal generating module can control the width of the two output pulses by controlling the delay times of the corresponding unilateral delay circuit. The signal combining module outputs the ATD signal having pulses at both the rising edge and falling edge of the address signal. The present application uses two unilateral delay circuits to control the width of the ATD signal at the rising edge and the falling edge of the address signal, thereby significantly preventing the width of the ATD signal from influence of the burr on the address line.

Abstract: There is disclosed an address transition detecting circuit in the present application. The address transition detecting circuit comprises two identical address transition detecting signal generating module, an inverter and a signal combining module. Both of the two address transition detecting signal generating module comprise a unilateral delay circuit for generating an output pulse at the rising edge of the address signal and an output pulse at the falling edge of the address signal. The address transition detecting signal generating module can control the width of the two output pulses by controlling the delay times of the corresponding unilateral delay circuit. The signal combining module outputs the ATD signal having pulses at both the rising edge and falling edge of the address signal.

Abstract: The present application provides a circuit and method for controlling internal test mode entry of an ASRAM chip. The circuit comprises an address code comparator for detecting whether address codes on an address bus of the ASRAM chip match a predefined validation code; a test mode detector for determining whether to let the ASRAM chip enter into an internal test mode; a test mode clock generator for generating a clock signal for the test mode decoder; and a test mode decoder for generating a test control signal. The circuit of the present application uses the existing pins of the ASRAM chip to input a special section of codes to trigger the ASRAM to enter into its internal test mode, thereby reducing the difficulty of testing the products.

Abstract: The present application provides a circuit and method for testing a memory device. The memory device has multiple blocks addressable via a plurality of address lines and capable of inputting and/or outputting data via a plurality of data lines.