Peripheral power domains

A method of operating an integrated-circuit device, the integrated-circuit device comprising:

• a processor;
• a first peripheral;
• a second peripheral;
• a bus system, connecting the processor, the first peripheral and second peripheral;
• a peripheral interconnect, separate from the bus system;
• wake-up logic, connected to the peripheral interconnect;
• a configuration memory;
• and
• a power controller,
• wherein:
• the first peripheral comprises a first peripheral interface module for outputting event signals to the peripheral interconnect;
• the peripheral interconnect provides a channel for receiving an event signal from the first peripheral and for providing the event signal to the second peripheral;
• the second peripheral comprises a configurable second peripheral interface module for initiating tasks on the second peripheral in response to event signals received from the peripheral interconnect, in accordance with second-peripheral configuration settings stored in the configuration memory;
• the first peripheral is in a first power domain;
• the second peripheral is in a second power domain;
• the wake-up logic is in a third power domain;
• and
• the power controller is configured to provide power to the third power domain whenever the first power domain or the second power domain is powered up, such that the wake-up logic is powered up whenever the first or second peripheral is powered up,
• wherein the method comprises:
• the first peripheral generating an event signal in response to a change of state within the first peripheral;
• the first peripheral outputting the event signal to the peripheral interconnect;
• the wake-up logic detecting the event signal generated by the first peripheral;
• the wake-up logic using the second-peripheral configuration settings to determine that the second peripheral interface module is configured to initiate a task in the second peripheral in response to the event signal;
• the wake-up logic instructing the power controller to power up the second peripheral, in response to determining that the second peripheral interface module is configured to initiate a task in the second peripheral in response to the event signal;
• the second peripheral receiving the event signal from the peripheral interconnect;
• and
• the second peripheral initiating the task on the second peripheral in response to the event signal received from the peripheral interconnect.