Serial Line Protocol for Embedded Devices

• US 20110072162A1
• Filed: 09/01/2010
• Published: 03/24/2011
• Est. Priority Date: 09/23/2009
• Status: Active Grant

• Current Assignee: Avago Technologies International Sales Pte Limited (Broadcom, Inc.)
• Original Assignee: LSI Corporation (Broadcom, Inc.)
• Inventors: Rysavy, Randal S.
• Granted Patent: US 8,504,737 B2
• Time in Patent Office: Days
• US Class Current: 710/5
• CPC Class Codes: G06F 12/0246 in block erasable memory, e.g. flash memory
• CPC Class Codes: G06F 12/1027 using associative or pseudo-associative address translation means, e.g. translation look-aside buffer [TLB]
• CPC Class Codes: G06F 13/14 Handling requests for interconnection or transfer
• CPC Class Codes: G06F 13/24 using interrupt G06F13/32 takes precedence
• CPC Class Codes: G06F 2212/7201 Logical to physical mapping or translation of blocks or pages
• CPC Class Codes: G06F 2212/7203 Temporary buffering, e.g. using volatile buffer or dedicated buffer blocks
• CPC Class Codes: G06F 2213/0028 Serial attached SCSI [SAS]
• CPC Class Codes: G06F 3/00 Input arrangements for transferring data to be processed into a form capable of being handled by the computer; Output arrangements for transferring data from processing unit to output unit, e.g. interface arrangements

Abstract

Described embodiments provide a transceiver for transferring data between a media controller and a host device through a communication link. The transceiver includes a first interrupt generator configured to i) generate a first interrupt when a command is received from the host device and ii) provide the received command to a receive buffer. A command processing module i) retrieves the received command from the receive buffer, ii) processes the received command, and iii) provides data request data in response to the received command to a transmit buffer. A datagram generator is configured to provide datagram data to the transmit buffer and a second interrupt generator is configured to generate a second interrupt when data in the transmit buffer is ready for transmission. The transmit buffer interleaves i) the data request data in response to the received command and ii) the datagram data, when provided to the communication link.

Claims

1. A method of processing, by a media controller, a command received from a host device coupled to the media controller by a communication link, the method comprising:

generating, by a first interrupt generator, a first interrupt when the command is received;

providing the received command to a receive buffer;

transmitting an acknowledge signal to the host device;

if the received command includes a data transfer from the host device;

transferring data from the host device to the receive buffer;

processing, by a command processing module of the media controller, the received command including the transferred data, if present;

if the received command includes a data transfer to the host device;

receiving a data request from the host device;

providing, by the command processing module, data corresponding to the data request to the transmit buffer; and

generating, by a second interrupt generator, a second interrupt when the data corresponding to the data request in the transmit buffer is ready for transmission;

providing, by a datagram generator of the media controller, datagram data to the transmit buffer; and

interleaving, by the transmit buffer, transmission of i) the data corresponding to the data request and ii) the datagram data on the communication link.

2. The method recited in claim 1, further comprising:

arbitrating access to the transmit buffer between the command processing module and the datagram generator.

3. The method recited in claim 1, wherein the interleaving of datagram data is performed asynchronously with respect to the transmission of the data corresponding to the data request.

4. The method recited in claim 1, wherein the received command is one of i) a write transfer command, ii) a read transfer command, and iii) a no transfer command, wherein

the write transfer command comprises one of i) writing one or more registers of the media controller, ii) writing one or more memory addresses of a buffer of the media controller, and iii) writing one or more addresses of a storage media coupled to the media controller;

and

the read transfer command comprises one of i) reading one or more registers of the media controller, ii) reading one or more memory addresses of the buffer of the media controller, and iii) reading one or more addresses of the storage media coupled to the media controller.

5. The method recited in claim 1, wherein the datagram data is of variable length and the datagram data comprises one or more of a timestamp, a sequence number of a process operating on the media controller, and log data documenting statistics of the media controller, the statistics comprising at least one of error codes and operating statistics.

21. The method of claim 4, wherein the storage media is a Redundant Array of Independent Disks (RAID) system comprising a plurality of storage devices and at least one media controller coupled to at least one corresponding storage device.

6. A machine-readable storage medium, having encoded thereon program code, wherein, when the program code is executed by a machine, the machine implements a method of processing, by a media controller, a command received from a host device coupled to the media controller by a communication link, the method comprising:

generating, by a first interrupt generator, a first interrupt when the command is received;

providing the received command to a receive buffer;

transmitting an acknowledge signal to the host device;

if the received command includes a data transfer from the host device;

transferring data from the host device to the receive buffer;

processing, by a command processing module of the media controller, the received command including the transferred data, if present;

if the received command includes a data transfer to the host device;

receiving a data request from the host device;

providing, by the command processing module, data corresponding to the data request to the transmit buffer; and

generating, by a second interrupt generator, a second interrupt when the data corresponding to the data request in the transmit buffer is ready for transmission;

providing, by a datagram generator of the media controller, datagram data to the transmit buffer; and

interleaving, by the transmit buffer, transmission of i) the data corresponding to the data request and ii) the datagram data on the communication link.

7. The machine-readable storage medium recited in claim 6, further comprising:

arbitrating access to the transmit buffer between the command processing module and the datagram generator.

8. The machine-readable storage medium recited in claim 6, wherein the interleaving of datagram data is performed asynchronously with respect to the transmission of the data corresponding to the data request.

9. The machine-readable storage medium recited in claim 6, wherein the received command is one of i) a write transfer command, ii) a read transfer command, and iii) a no transfer command, wherein

the write transfer command comprises one of i) writing one or more registers of the media controller, ii) writing one or more memory addresses of a buffer of the media controller, and iii) writing one or more addresses of a storage media coupled to the media controller;

and

the read transfer command comprises one of i) reading one or more registers of the media controller, ii) reading one or more memory addresses of the buffer of the media controller, and iii) reading one or more addresses of the storage media coupled to the media controller.

10. The machine-readable storage medium recited in claim 6, wherein the datagram data is of variable length and the datagram data comprises one or more of a timestamp, a sequence number of a process operating on the media controller, and log data documenting statistics of the media controller, the statistics comprising at least one of error codes and operating statistics.

11. A transceiver for transferring data between a media controller and a host device through a communication link, the transceiver comprising:

a first interrupt generator configured to i) generate a first interrupt when a command is received from the host device and ii) provide the received command to a receive buffer;

a command processing module configured to i) retrieve the received command from the receive buffer, ii) process the received command, and iii) provide data request data in response to the received command to a transmit buffer;

a datagram generator configured to provide datagram data to the transmit buffer;

a second interrupt generator configured to generate a second interrupt when data request data in the transmit buffer is ready for transmission;

wherein the transmit buffer is further configured to interleave i) the data request data in response to the received command and ii) the datagram data, when provided to the communication link.

12. The transceiver recited in claim 11, further comprising a multiplexer adapted to control access to the transmit buffer by the command processing module and the datagram generator.

13. The transceiver recited in claim 11, wherein the data request data in response to the received command and the datagram data are interleaved asynchronously.

14. The transceiver recited in claim 11, wherein the transceiver is a universal asynchronous receiver/transmitter (UART).

15. The transceiver recited in claim 11, wherein the communication link is an RS-232 serial link.

16. The transceiver recited in claim 11, wherein the communication link operates in accordance with the serial line internet protocol (SLIP).

17. The transceiver recited in claim 11, wherein the received command is one of i) a write transfer command, ii) a read transfer command, and iii) a no transfer command, wherein the write transfer command receives data from the host device and the read transfer command transmits data to the host device.

18. The transceiver recited in claim 17, wherein

the write transfer command comprises one of i) a command to write one or more registers of the media controller, ii) a command to write one or more memory addresses of a buffer of the media controller, and iii) a command to write one or more addresses of a storage media coupled to the media controller;

the read transfer command comprises one of i) a command to read one or more registers of the media controller, ii) a command to read one or more memory addresses of the buffer of the media controller, and iii) a command to read one or more addresses of the storage media coupled to the media controller.

19. The transceiver recited in claim 11, wherein the datagram data is of variable length and the datagram data comprises one or more of a timestamp, a sequence number of a process operating on the media controller, and log data documenting statistics of the media controller, the statistics comprising at least one of error codes and operating statistics.

20. The transceiver recited in claim 11, wherein the apparatus is implemented in a monolithic integrated circuit chip.