Deferred tuple space programming of expansion modules

A peripheral controller for coupling a peripheral to a host computing device, and for use with an optional external memory including external tuples, the peripheral controller comprising:

• a host interface implementing an expansion bus protocol compatible with the host computing device;
• a memory interface implementing a memory bus protocol compatible with the external memory;
• a host-visible memory configured to store operational tuples;
• an internal initialization memory including default internal tuples;
• control logic coupled to the host interface, the memory interface, the host-visible memory, and the internal initialization memory;
• wherein the peripheral controller is configurable in one of a first and a second I/O-pin configurations, the first and the second I/O-pin configurations being mutually exclusive;
• wherein if the control logic determines that the external memory is present and programmed then the host-visible memory is initialized to include the external tuples;
• wherein if the control logic determines that the external memory is blank, then the host-visible memory is initialized to include the internal tuples;
• wherein if the control logic determines that the external memory is absent and the peripheral controller is in the first I/O-pin configuration, then the host-visible memory is initialized to include the internal tuples;
• and
• wherein if the control logic determines that the external memory is absent and the peripheral controller is in the second I/O-pin configuration, then the host-visible memory is initialized to include no tuples.

A method for deferring the final programming of expansion module tuple space in an expansion module for a host, the expansion module optionally having a reprogrammable non-volatile memory having external tuples, the method comprising:

• providing the host and the expansion module, the expansion module including a peripheral controller and optionally the reprogrammable non-volatile memory having the external tuples, the peripheral controller having a host-visible memory and an internal initialization memory including internal tuples, the peripheral controller having I/O-pins capable of a plurality of configurations;
• coupling the expansion module to the host for the first time;
• in the peripheral controller, determining the status of the reprogrammable non-volatile memory;
• in the peripheral controller, if the reprogrammable non-volatile memory is present and programmed, initializing operational tuples in the host-visible memory to include the external tuples;
• in the peripheral controller, if the reprogrammable non-volatile memory is absent, initializing provisional operational tuples in the host-visible memory to include the internal tuples;
• in the peripheral controller, if the reprogrammable non-volatile memory is blank and the I/O-pins correspond to a first configuration, initializing provisional operational tuples in the host-visible memory to include the internal tuples;
• in the peripheral controller, if the reprogrammable non-volatile memory is blank and the I/O-pins correspond to a second configuration, initializing provisional operational tuples in the host-visible memory to have no tuples;
• in the peripheral controller, conveying the pre-initialization status of the reprogrammable non-volatile memory via the value of at least one of the operational tuples initialized in the host-visible memory;
• the expansion module providing at least basic functionality to the host;
• using host-based software to access the operational tuples initialized in the host-visible memory and determine the pre-initialization status of the reprogrammable non-volatile memory;
• in the host, selecting whether or not to update the operational tuples initialized in the host-visible memory;
• if updating is selected, the host commanding the peripheral controller to selectively store finalized operational tuples in at least one of the host-visible memory and the optional reprogrammable non-volatile memory;
• and
• whereby the reprogrammable non-volatile memory need not be present or pre-programmed prior to the first use of the expansion module.