Abstract: A method and apparatus for optimizing clock distribution in a circuit to reduce the effect of power supply noise. Parameters are determined including: a response curve of a power source for a circuit, a delay sensitivity of a clock net in the circuit to the power source, a delay sensitivity of a data net in the circuit to the power source, a data delay for the data net, and a clock delay for the clock net. The clock delay is adjusted to reduce the effect of power supply noise on the data net. The adjusting is based on the response curve of the power source, the delay sensitivity of the clock net, the delay sensitivity of the data net, the data delay, and the clock delay. The adjusting includes adding a pre-distribution clock delay.

Abstract: The present invention provides a data processing apparatus and method for testing power management instructions. The data processing apparatus comprises a processor for executing data processing instructions including power management instructions, at least one of the power management instructions being a command power management instruction. A power management controller is also provided for receiving command data from the processor when a command power management instruction is executed by the processor, and to control power management logic to perform an associated set of power management functions dependent on the command data. The data processing apparatus includes first power management logic controllable by the power management controller, with the power management controller also having an interface to enable communication with additional power management logic.

Abstract: Methods and systems for generating and synchronizing multiple clocks are disclosed herein that have extremely low skew across multiple channels and latency that is both minimal and well-defined. A phase-locked loop circuit generates a plurality of clock signals to synchronize channel circuits that receive core data streams. The channel circuits convert the core data streams into serial data streams. The phase-locked loop circuit or another phase-locked loop circuit generates a core clock signal for the registered transfer of the core data streams to the channel circuits. One or more of the plurality of clock signals may be distributed to the channel circuits by a register-to-register transfer.