Advanced Micro Devices Corporation

Michael Q Co

Nur Mohammad Baksh

Daniel William Bailey

Vibhor Mittal

Abhishek Sharma

Kedar Karthykeyan

A method includes generating a functional clock signal, a scan clock signal, and a delayed clock signal based on a control clock signal and a scan enable signal. The method includes precharging or predischarging a differential pair of nodes in a first latch using the delayed clock signal and a voltage on a first power supply node and controlling a second latch using the delayed clock signal. The method includes latching data input by the first latch using the functional clock signal in a functional mode of operation and latching scan data by the first latch using the scan clock signal in a scan mode of operation.

Split-scan sense amplifier flip-flop

A pre-discharged edge-triggered flip-flop, in which internal nodes determinative of an output signal are discharged to VSS prior to an evaluation phase of a clock signal, is provided to enable improved clock-to-output response times when provided with a rising edge of a clock pulse. In operation, during a pre-discharge phase of the clock signal, multiple internal nodes of a differential master latch circuit of the flip-flop are discharged to VSS. In response to a rising edge of the clock signal signaling the beginning of an evaluation phase, one of the internal nodes (selected depending on the logical value of an input signal to the flip-flop) is charged to VDD while other of the internal nodes remain at VSS. A single clock signal inverter is disposed between the input clock signal and a multiplexer providing the output data signal.

Pre-discharged bypass flip-flop circuit

In one form, a scan flip-flop includes a clock gating cell and a dedicated clock flip-flop. The clock gating cell provides an input clock input signal as a scan clock signal when a scan shift enable signal is active, and provides the input clock signal as a data clock signal when the scan shift enable signal is inactive. The dedicated clock flip-flop stores a data input signal and provides the data input signal, so stored, as a data output signal in response to transitions of the data clock signal, and stores a scan data input signal and provides the scan data input signal, so stored, as the data output signal in response to transitions of the scan clock signal. The clock gating cell may further provide the input clock signal as the data clock signal when both a scan shift enable signal is inactive and a data enable signal is active.

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Austin, TX, United States of America

Michael Q Co