Abstract: A method for serial interface clock domain crossing includes identifying a data communication command received over a serial interface. An address is decoded to determine whether the address falls within a direct latch address range of a register bank. Data is communicated over the serial interface. A multiplexed output clock is generated, for writing to and reading from the register bank, based on at least one of a current system operating state and a refresh control signal from a host processor.

Abstract: Aspects of power mode register reduction and power rail bring up enhancements are described. In one embodiment, an operating parameter for a first power rail is set by power management circuit according to a predetermined programmed setting. In connection with a wait time, the power rail is enabled, and a processor is released to start. In turn, at least one of a command to modify the operating parameter for the first power rail or a command to set an operating parameter for a second power rail is received from the processor over a high speed interface. By accessing a grouped operating register for a group of power rails, the processor can update or modify settings of an entire group of power rails at one time. In connection with the processor, the power management circuit can power up a plurality of power rails in a flexible and efficient manner.

Abstract: A method for serial interface clock domain crossing includes identifying a data communication command received over a serial interface. An address is decoded to determine whether the address falls within a direct latch address range of a register bank. Data is communicated over the serial interface. A multiplexed output clock is generated, for writing to and reading from the register bank, based on at least one of a current system operating state and a refresh control signal from a host processor.

Abstract: Aspects of a clock domain crossing serial interface, direct latching over the serial interface, and response codes are described. In various embodiments, a data communication command received over a serial interface is identified, and an address received over the serial interface is resolved to access a register bank. In a write operation, depending upon whether the address falls within a direct latch address range of the register bank, data may be directly latched into a direct latch register of the register bank or into a first-in-first-out register. For both read and write operations, reference may be made to a status register of the serial interface to identify or mitigate error conditions, and wait times may be relied upon to account for a clock domain crossing. After each of the read and write operations, a response code including a status indictor may be communicated.

Abstract: Aspects of power mode register reduction and power rail bring up enhancements are described. In one embodiment, an operating parameter for a first power rail is set by power management circuit according to a predetermined programmed setting. In connection with a wait time, the power rail is enabled, and a processor is released to start. In turn, at least one of a command to modify the operating parameter for the first power rail or a command to set an operating parameter for a second power rail is received from the processor over a high speed interface. By accessing a grouped operating register for a group of power rails, the processor can update or modify settings of an entire group of power rails at one time. In connection with the processor, the power management circuit can power up a plurality of power rails in a flexible and efficient manner.

Abstract: Aspects of a clock domain crossing serial interface, direct latching over the serial interface, and response codes are described. In various embodiments, a data communication command received over a serial interface is identified, and an address received over the serial interface is resolved to access a register bank. In a write operation, depending upon whether the address falls within a direct latch address range of the register bank, data may be directly latched into a direct latch register of the register bank or into a first-in-first-out register. For both read and write operations, reference may be made to a status register of the serial interface to identify or mitigate error conditions, and wait times may be relied upon to account for a clock domain crossing. After each of the read and write operations, a response code including a status indictor may be communicated.