Abstract: Clock multiplexer circuitry outputs one of a first or second clock signal. First selection circuitry is connected in series with first counter circuitry. The first selection circuitry and the first counter circuitry receive a first clock signal and a first selection signal. A first control signal is generated based on the first clock signal and the first selection signal. Second selection circuitry is connected in series with second counter circuitry. The second selection circuitry and the second counter circuitry receive a second clock signal and a second selection signal. A second control signal is generated based on the second clock signal and the second selection signal. The output circuitry is connected to the first counter circuitry and the second counter circuitry. The output circuitry outputs one of the first clock signal and the second clock signal based on the first control signal and the second control signal.

Abstract: Clock multiplexer circuitry outputs one of a first or second clock signal. First selection circuitry is connected in series with first counter circuitry. The first selection circuitry and the first counter circuitry receive a first clock signal and a first selection signal. A first control signal is generated based on the first clock signal and the first selection signal. Second selection circuitry is connected in series with second counter circuitry. The second selection circuitry and the second counter circuitry receive a second clock signal and a second selection signal. A second control signal is generated based on the second clock signal and the second selection signal. The output circuitry is connected to the first counter circuitry and the second counter circuitry. The output circuitry outputs one of the first clock signal and the second clock signal based on the first control signal and the second control signal.

Abstract: Two retention flip-flop topologies that utilize a data retention control circuit and a slave/retention latch (sub-circuit) to reliably retain a data bit during standby/sleep operating modes without the need for a local clock signal. The slave/retention latch is controlled using a local clock signal to store sequentially received data bit values during normal operating modes. During standby/sleep modes, the local clock signal is de-activated (i.e., by turning off the supply voltage provided to the local clock generator circuit), and the data retention control circuit operates in accordance with an externally supplied retention enable control signal to both isolate and control the slave/retention latch such that a last-received data bit value is reliably retained in the slave/retention latch. When normal operation is resumed, the local clock signal is re-activated, and the data retention control circuit controls the slave/retention latch to pass the last-received data bit value to an output driver.

Abstract: Two retention flip-flop topologies that utilize a data retention control circuit and a slave/retention latch (sub-circuit) to reliably retain a data bit during standby/sleep operating modes without the need for a local clock signal. The slave/retention latch is controlled using a local clock signal to store sequentially received data bit values during normal operating modes. During standby/sleep modes, the local clock signal is de-activated (i.e., by turning off the supply voltage provided to the local clock generator circuit), and the data retention control circuit operates in accordance with an externally supplied retention enable control signal to both isolate and control the slave/retention latch such that a last-received data bit value is reliably retained in the slave/retention latch. When normal operation is resumed, the local clock signal is re-activated, and the data retention control circuit controls the slave/retention latch to pass the last-received data bit value to an output driver.

Abstract: A circuit is disclosed. The circuit includes an output driver with a pull-up device, and a pull-down device. The circuit also includes a pre-driver, configured to generate a first signal for the pull-up device and to generate a second signal for the pull-down device, a first positive feedback circuit configured to increase the slew rate of the first signal in response to a transition in the second signal, and a second positive feedback circuit configured to increase the slew rate of the second signal in response to a transition in the first signal.

Abstract: A multi-bit flip-flop (MBFF) includes a plurality of 1-bit flip-flops, each having an input data selection circuit that receives a data signal and a scan data signal. The MBFF also includes a local signal generation circuit that receives a global clock signal and a global scan enable signal, and in response, provides local control signals, wherein each of the local control signals is generated in response to both the global clock signal and the global scan enable signal. The local control signals are provided to the input data selection circuits, and exclusively control the input data selection circuits to route either the input data signal or the scan input data signal as a master data bit, reducing transistor requirements. Local clock signals may be generated by the local signal generation circuit in response to the global clock signal, and may exclusively control data transfer within the flip-flops, improving setup time.

Abstract: A multi-bit flip-flop (MBFF) includes a plurality of 1-bit flip-flops, each having an input data selection circuit that receives a data signal and a scan data signal. The MBFF also includes a local signal generation circuit that receives a global clock signal and a global scan enable signal, and in response, provides local control signals, wherein each of the local control signals is generated in response to both the global clock signal and the global scan enable signal. The local control signals are provided to the input data selection circuits, and exclusively control the input data selection circuits to route either the input data signal or the scan input data signal as a master data bit, reducing transistor requirements. Local clock signals may be generated by the local signal generation circuit in response to the global clock signal, and may exclusively control data transfer within the flip-flops, improving setup time.

Abstract: A circuit is disclosed. The circuit includes an output driver with a pull-up device, and a pull-down device. The circuit also includes a pre-driver, configured to generate a first signal for the pull-up device and to generate a second signal for the pull-down device, a first positive feedback circuit configured to increase the slew rate of the first signal in response to a transition in the second signal, and a second positive feedback circuit configured to increase the slew rate of the second signal in response to a transition in the first signal.