Intelligent, extensible SIE peripheral device
View Patent ↗An apparatus for coupling a peripheral device to a host comprising an interface circuit and a logic circuit. The interface circuit may be configured to (i) receive a request from the host and (ii) present a response to the host. The logic circuit may be configured to (i) generate the response when the request is serviceable by the apparatus or (ii) pass the request to an external circuit when the request is not serviceable by the apparatus.
1. An apparatus for coupling a peripheral device to a host comprising:
an interface circuit configured to receive a request from said host and present a response to said request to said host; and
a serial interface engine (SIE) coupled to said interface circuit and configured to (i) automatically generate said response to said request when said request is a first type of request that said serial interface engine is configured to recognize and (ii) pass (a) said request from said interface circuit to an external circuit and (b) said response to said request from said external circuit to said interface circuit when said request is a second type of request that said serial interface engine is not configured to recognize.
2. The apparatus according to claim 1 , wherein said interface circuit comprises a serial interface.
3. The apparatus according to claim 1 , wherein said external circuit comprises a processor.
4. The apparatus according to claim 3 , wherein said external circuit comprises a processor selected from the group consisting of a digital signal processor (DSP), a microprocessor, and an application specific integrated circuit (ASIC).
5. The apparatus according to claim 1 , wherein said apparatus comprises a universal serial bus (USB) peripheral device.
6. The apparatus according to claim 1 , wherein said serial interface engine is configured to generate said response to said first type of request using information received from said external circuit.
7. The apparatus according to claim 6 , wherein said serial interface engine further comprises a memory configured to store said information and said information comprises a descriptor table.
8. The apparatus according to claim 1 , wherein said serial interface engine is further configured to (i) automatically service an enumeration request, (ii) to handle physical layer requirements, (iii) to handle a packet protocol layer, and (iv) to maintain one or more endpoints.
9. The apparatus according to claim 1 , wherein said serial interface engine is further configured to handle USB chapter 9 protocol communications transparently to said external circuit and said first type of request comprises a request as defined in Chapter 9 of the Universal Serial Bus (USB) Specification, revision 2.0.
10. The apparatus according to claim 1 , wherein said second type of request comprises a request selected from the group consisting of a class request, a vendor request, a custom driver request, and requests implemented to support USB specification changes and enhancements.
11. The apparatus according to claim 1 , wherein said external circuit is configured to generate a stall signal as said response when said request of said second type is not recognized by said external circuit.
12. An apparatus comprising:
means for receiving a request from a host and presenting a response to said request to said host;
means for generating said response automatically when said request is of a first type recognized by said generating means; and
means for passing (i) said request from said receiving and presenting means to an external circuit and (ii) said response from said external circuit to said receiving and presenting means when said request is of a second type not recognized by said generating means.
13. A method for interfacing a peripheral device to a host comprising the steps of:
receiving a request from said host;
automatically responding to said request within a serial interface engine when said request is a first type of request that said serial interface engine is configured to recognize;
when said request is a second type of request that said serial interface engine is not configured to recognize, passing said request to an external circuit;
receiving a response to said request from said external circuit when said request is of said second type; and
passing on said response to said host.
14. The method according to claim 13 , further comprising the step of:
generating said response as a stall command when said request is not recognized by said external circuit.
15. The method according to claim 13 , wherein said external circuit comprises a processor selected from the group consisting of a digital signal processor (DSP), a microprocessor, and an application specific integrated circuit (ASIC).
16. The method according to claim 13 , wherein said requests are received via a serial bus in accordance with the Universal Serial Bus (USB) Specification, revision 1.0, 1.1, or 2.0.
17. The method according to claim 13 , wherein said first type of request comprises an enumeration request.
18. The method according to claim 13 , wherein said second type of request presented to said external circuit comprises a request selected from the group consisting of a class request, a vendor request, a custom driver request, and a request implemented to support changes and/or enhancements to a communication protocol.
19. The method according to claim 17 , wherein the step of automatically responding to said request comprises enumerating said peripheral device without passing said enumeration request to said external circuit.
20. The method according to claim 13 , further comprising the step of receiving one or more descriptor tables from said external circuit.