Abstract: An integrated circuit comprises a double frequency clock generator and a double input generator to test semiconductor devices at frill frequency using a half frequency tester. A clock generator circuit and a test data generator circuit provides differential clock and test data signals at a normal (1× mode) and high-speed rate (2× mode) to a device under test. In 1× mode, clock generator and test data generator circuits pass through the differential clock signals and test data values provided by a testing device unchanged. In 2× mode, the clock generator circuit receives the differential clock signal as clock signals clk and clkb and outputs clock signals clk_int and clkb_int that are inverted signals and twice the frequency of clk and clkb. The test data generator circuit clocks test data values into registers according to clk_int and clkb_int to generate an increased number of test data values per clock signal clk.

Abstract: A chain of boundary scan registers is configured to use a two-phase clock signal to avoid data timing race conditions. The two-phase clock signal is generated according to a two-phase clock generator, which includes two self-timed clock pulse generators for each boundary scan register. The two-phase clock generator locally generates a self-timed clock pulse at the rising edge of a clock signal, which triggers a first stage of the boundary scan register. The two-phase clock generator also generates a self-timed clock pulse at the falling edge of the input clock signal, which triggers a second stage of the boundary scan register. The two-phase clock controlled boundary scan register includes two latches, each latch is triggered by one of the self-timed clock pulse generated locally from the rising and falling edge of the input clock signal.

Abstract: A decoding signal circuit is configured to generate a dual operation decoding signal that enables a read operation and a write operation to be performed in one clock cycle. The decoding signal circuit is configured such that a read decoding signal and a write decoding signal are generated and multiplexed together to form the dual operation decoding signal. The memory device receives a read address and a write address consecutively in one cycle to generate the dual operation decoding signal. A single operation, such as a read only operation or a write only operation, can be performed as well as the dual operation of performing the read operation and the write operation in the same cycle.