Message passing circuitry and method

Message passing circuitry for message passing between circuit nodes;

• the message passing circuitry comprising:
• lookup circuitry responsive to a producer request indicating message data provided on a target message channel by a producer node of the circuit nodes, to obtain, from a channel consumer information structure for specifying channel consumer information for a plurality of message channels and one or more consumer nodes of the circuit nodes subscribing to the message channels, selected channel consumer information associated with a given consumer node subscribing to the target message channel;
• and
• control circuitry to:
• write the message data indicated by the producer request to a location associated with an address in a consumer-defined region of address space determined based on the selected channel consumer information;
• and
• when an event notification condition is satisfied for the target message channel and the given consumer node:
• when event notifications for the target message channel are to be provided to the given consumer node in response to the event notification condition, provide the event notification to the given consumer node;
• and
• when event notifications for the target message channel are to be provided on an event notification channel of said plurality of message channels, cause event notification data to be written to a location associated with an address in a consumer-defined region of address space determined based on event notification channel consumer information associated with the event notification channel;
• in which in response to a channel subscription request from a subscribing consumer node specifying an identifier associated with a given message channel, the control circuitry is configured to update the channel consumer information structure to specify channel consumer information for the subscribing consumer node subscribing to the given message channel.

A system-on-chip comprising:

• a plurality of nodes;
• and
• message passing circuitry to pass messages between the nodes, the message passing circuitry comprising:
• lookup circuitry responsive to a producer request indicating message data provided on a target message channel by a producer node of the system-on-chip, to obtain, from a channel consumer information structure for specifying channel consumer information for a plurality of message channels and one or more consumer nodes of the system-on-chip subscribing to the message channels, selected channel consumer information associated with a given consumer node subscribing to the target message channel;
• and
• control circuitry to:
• write the message data indicated by the producer request to a location associated with an address in a consumer-defined region of address space indicated by the selected channel consumer information;
• and
• when an event notification condition is satisfied for the target message channel and the given consumer node:
• when event notifications for the target message channel are to be provided to the given consumer node in response to the event notification condition, provide the event notification to the given consumer node;
• and
• when event notifications for the target message channel are to be provided on an event notification channel of said plurality of message channels, cause event notification data to be written to a location associated with an address in a consumer-defined region of address space determined based on event notification channel consumer information associated with the event notification channel.