Method and device for controlling communications with a serial bus

On a node coupled to a serial bus, a communication controller comprising:

• one or more tasks coupled to the serial bus each task having its own queue, each task structured to perform a specialized function responsive to data retrieved from their respective queue;
• a transaction interface having a transaction interface queue, the transaction interface structured to accept data packets from the bus and to perform actions only in response to calls from a task and to data contained within the data packets for isochronous and asynchronous data transfer;
• and
• a dispatcher having a dispatcher queue, the dispatcher structured to accept information sent to the dispatcher queue only in response to calls from a task;
• wherein each task scheduled to execute when data is placed in its queue by the transaction interface or any of the other tasks, each task structured to remove data from the top of its queue when the data is no longer being operated on, each task executed after the dispatcher issues a start command for that task, the start command issued by the dispatcher only when the dispatcher has data placed in its queue indicating that the particular task is not presently executing, and each task structured to operate concurrently with and independently from all of the other tasks.

A method of communicating over a serial bus comprising, at a node on the serial bus:

• receiving packets of information from the serial bus at a transaction interface that is configured to perform isochronous and asynchronous data transfer:
• decoding the packets and analyzing the information received only in response to a call from a task to determine if a service or a task should be called;
• if a service or task is to be called, formatting data to be placed into a queue associated with one of a plurality of services or tasks;
• placing the data into the respective queue of the service or the service or task being called;
• starting the service or task if no data was already present in the respective queue of the service or task being called;
• removing data from the queue when it is no longer being operated upon by the service or task;
• and
• continue operating by the service or task being called until all data is removed from the queue.

An electronic readable medium whose contents allow an electronic device to communicate over a serial bus comprising, at a node on the serial bus the steps of:

• receiving packets of information from the bus at a receiving bay of a transaction interface that is configured to perform isochronous and asynchronous data transfer;
• decoding the packets and analyzing the information received only in response to a call from a task to determine if a task should be called;
• if a task is to be called, formatting data to be placed into a queue associated with at least one of a plurality of tasks and queuing the data into the respective queue of the task being called;
• starting the task if the data was placed in the top of the respective queue of the task being called;
• and
• continue operating by the task being called until all data is removed from the queue.