Gateway apparatus and routing method

• US 7,787,479 B2
• Filed: 04/27/2006
• Issued: 08/31/2010
• Est. Priority Date: 04/28/2005
• Status: Expired due to Fees

• Current Assignee: Fujitsu Semiconductor Limited (Fujitsu Limited)
• Original Assignee: Fujitsu Ten Limited (DENSO Corporation), Fujitsu Limited
• Inventors: Matsuo, Tomohiro, Shimoji, Naoto, Kusumoto, Masayoshi, Kawasoe, Nobuaki, Takahashi, Junji, Furuya, Akiko, Nishihashi, Susumu, Umezaki, Yasuyuki, Noumi, Kaoru, Kasame, Tomohide, Ishikawa, Yukio, Takatori, Tsuyoshi
• Primary Examiner(s): Kumar; Pankaj
• Assistant Examiner(s): Tsegaye; Saba
• Application Number:
  US11/412,048
• Publication Number:
  US 20060271694A1
• Time in Patent Office: 1,587 Days
• Field of Search: 370352-356, 370/389, 370/392, 370/401, 370/412, 370/413
• US Class Current: 370/401
• CPC Class Codes: H04L 12/4135 using bit-wise arbitration
• CPC Class Codes: H04L 12/4625 Single bridge functionality, e.g. connection of two networks over a single bridge
• CPC Class Codes: H04L 2012/40215 Controller Area Network CAN
• CPC Class Codes: H04L 45/00 Routing or path finding of packets in data switching networks routing or path finding in wireless networks H04W40/00
• CPC Class Codes: H04L 47/10 Flow control; Congestion control
• CPC Class Codes: H04L 49/254 Centralised controller, i.e. arbitration or scheduling
• CPC Class Codes: H04L 49/501 Overload detection
• CPC Class Codes: H04L 49/555 Error detection
• CPC Class Codes: H04L 49/90 Buffering arrangements
• CPC Class Codes: H04L 49/901 using storage descriptor, e.g. read or write pointers
• CPC Class Codes: H04L 49/9078 using an external memory or storage device

Abstract

There is provided a gateway apparatus that controls a forwarding process of frame data between multiple communication channels, said gateway apparatus including a search engine that is respectively provided for each of the multiple communication channels to route the frame data between the multiple communication channels, and a first storage portion that is respectively provided for each of the multiple communication channels to temporarily stores the frame data routed.

Claims

1. A vehicle gateway apparatus that controls a forwarding process of frame data between multiple communication channels, said vehicle gateway apparatus comprising:

a plurality of storage portions, having transmission storage portions and reception storage portions, provided for each of the multiple communication channels;

a routing unit that retrieves frame data from a reception storage region in one of the reception storage portions and that divides the frame data into frame data to be sent to a controller and the frame data to be sent to a hardware search engine according to the reception storage region from which the frame data is retrieved, the frame data being divided according to an identification number respectively recorded in the frame data and being respectively stored in the reception storage region in one of the reception storage portions;

the controller, controlled by software programs, that executes a routing process that receives the frame data sent from the routing unit and transmits the frame data to a transmission storage region in one of the transmission storage portions prepared for a communication channel being used by an entry to which the frame data is sent;

a first routing map storing portion that stores a plurality of routing maps used by the hardware search engine;

the hardware search engine, that executes a routing process using a routing map that receives the frame data sent from the routing unit and transmits the frame data to a transmission storage region in one of the transmission storage portions prepared for a communication channel being used by an entry to which the frame data is sent, regardless to the routing process by the controller;

a first arbitration unit provided for each of the multiple communication channels that inputs frame data transmitted from the controller and frame data transmitted from the hardware search engine, and arbitrates which of the frame data to be stored in each transmission storage portion; and

a state management portion that retrieves according to a state of the vehicle, a routing map prepared for an initialization time from the first routing map storing portion in the initialization time when an engine of the vehicle is started, and transmits the routing map to the hardware search engine to have the hardware search engine execute a routing using the routing map prepared for the initialization time,

and when the state of the vehicle is changed and receives the controller'"'"'s add request to increase a number of the multiple communication channels or a number of entries which transmit and receive the frame data by using the communication channels,

retrieves a routing map prepared for the time of adding the number of the communication channels or the number of the entries from the first routing map storing portion, and transmits the routing map to have the hardware search engine execute a routing using the routing map prepared for the time of adding the number of the communication channels or the number of entries.

2. The vehicle gateway apparatus as claimed in claim 1, further comprising multiple FIFO memories having multiple stages that are respectively provided for each of the multiple communication channels to temporarily store the frame data routed by the hardware search engine;

the first arbitration unit that inputs the frame data transmitted from the controller and the frame data retrieved from the multiple FIFO memories.

3. The vehicle gateway apparatus as claimed in claim 2, wherein the hardware search engine respectively provided for each of the multiple communication channels is provided with a routing map used for a channel selection of the frame data.

4. The vehicle gateway apparatus as claimed in claim 3, comprising a second arbitration unit that arbitrates the multiple communication channels, when the frame data routed by the hardware search engine is stored in the multiple FIFO memories.

5. The vehicle gateway apparatus as claimed in claim 4, wherein:

the second arbitration unit includes a register in which a priority is set for each of the multiple communication channels; and

the frame data is written into the multiple FIFO memories according to the priority, when multiple pieces of frame data are simultaneously written into the multiple FIFO memories.

6. The vehicle gateway apparatus as claimed in claim 2, comprising a DMA controller that forwards the frame data routed and stored in the multiple FIFO memories to a transmission storage portion prepared for a communication channel being used by an entry to which the frame data is sent.

7. The vehicle gateway apparatus as claimed in claim 2, comprising counter portions that count the number of pieces of frame data stored in each of the multiple FIFO memories.

8. The vehicle gateway apparatus as claimed in claim 7, wherein the hardware search engine outputs an interrupt signal to the controller that controls the vehicle gateway apparatus, when the number of pieces of frame data counted by the counter portion reaches a given number.

9. The vehicle gateway apparatus as claimed in claim 2, comprising a register that sets validity or invalidity of the multiple FIFO memories provided for each of the multiple communication channels.

10. The vehicle gateway apparatus as claimed in claim 2, wherein the hardware search engine determines an overflow of the multiple FIFO memories, when the frame data is transferred to the multiple FIFO memories and exceeds the number of pieces of frame data that can be stored in the multiple FIFO memories, and outputs an interrupt signal that notifies an error to the controller that controls the vehicle gateway apparatus.

11. The vehicle gateway apparatus as claimed in claim 2, wherein the hardware search engine determines a routing error, when there is no forwarding destination communication channel to which the frame data is forwarded, when a forwarding destination communication channel is invalid, when there is no multiple FIFO memories in which the frame data is to be stored, or when the multiple FIFO memories are invalid, and outputs an interrupt signal that notifies an error to the controller that controls the vehicle gateway apparatus.

12. The vehicle gateway apparatus as claimed in claim 2, wherein one hardware search engine and one multiple FIFO memories are provided for the multiple communication channels.

13. The vehicle gateway apparatus as claimed in claim 2, further comprising a parallel buffer separately provided from the multiple FIFO memories to store the frame data routed by the hardware search engine.

14. The vehicle gateway apparatus as claimed in claim 13, wherein:

the hardware search engine stores the frame data having a high priority in the parallel buffer; and

the controller acquires the frame data having the high priority from the parallel buffer.

15. The vehicle gateway apparatus as claimed in claim 2, further comprising a protocol converter that implements a protocol conversion of first frame data before stored in the multiple FIFO memories and second frame data retrieved from the multiple FIFO memories.

16. The vehicle gateway apparatus as claimed in claim 1, wherein the hardware search engine comprises:

a second routing map storing portion that stores a routing map transmitted from the state management portion;

an address generator that generates an address in the routing map;

a routing map portion that obtains routing information of the address from the routing map; and

a comparator that compares a first ID included in the routing information obtained from the routing map and a second ID included in the frame data, obtains a forwarding destination communication channel from the routing map when the first ID matches the second ID.

17. The vehicle gateway apparatus as claimed in claim 1, wherein the hardware search engine discards the frame data having a format that is not registered in the routing map.

18. The vehicle gateway apparatus as claimed in claim 1, wherein the hardware search engine applies an additional piece of data that represents a recorded position of the frame data necessary for forwarding the frame data.

19. The vehicle gateway apparatus as claimed in claim 1, wherein the hardware search engine outputs an interrupt signal to the controller that controls the vehicle gateway apparatus, when there is a routing error at the time of routing the frame data.

20. The vehicle gateway apparatus as claimed in claim 1, wherein the hardware search engine implements an error check of the routing map, when the hardware search engine determines that the frame data should be routed by searching the routing map.

21. The vehicle gateway apparatus as claimed in claim 1, comprising a timer that counts a period from when the frame data routed is received to when the frame data is forwarded to a forwarding destination communication channel,

wherein the controller that controls the vehicle gateway apparatus detects a holding time of the frame data with the use of the period counted by the timer.

22. The vehicle gateway apparatus as claimed in claim 1, further comprising a selector that adjusts timings when multiple pieces of frame data forwarded via the multiple communication channels are input into the hardware search engines.

23. The vehicle gateway apparatus as claimed in claim 1, wherein the controller refers to a data label applied to the frame data to implement a data process, a forwarding process, and a fail safe process.

24. The vehicle gateway apparatus as claimed in claim 1, further comprising a register that stores at least operation setting information of the vehicle gateway apparatus and routing setting information,

wherein the routing portion operates according to the operation setting information and the routing setting information.

25. The vehicle gateway apparatus as claimed in claim 1, wherein the hardware search engine implements a validity check of map information for routing while searching for the map information or idling.

26. The vehicle gateway apparatus as claimed in claim 25, wherein the number of entries is changed according to a forward control function of the vehicle gateway apparatus, the entries being respectively provided for the multiple communication channels and registered as the map information.

27. The vehicle gateway apparatus as claimed in claim 1, wherein the state management portion retrieves only data necessary for each of the multiple communication channels at the time of retrieving the map information from the first routing map storing portion.

28. The vehicle gateway apparatus as claimed in claim 27, wherein the hardware search engine implements an error check of the map information received from the state management portion.

29. The vehicle gateway apparatus as claimed in claim 1, further comprising a state monitoring block that selectively operates at least the routing portion and the multiple FIFO memories according to a state of a forward control function.

30. The vehicle gateway apparatus as claimed in claim 1, wherein the hardware search engine masks an ID number of the frame data at the time of retrieving entry data having a forwarding destination of the frame data received from map information, and detects the entry data of a corresponding communication channel.

31. A routing method that controls a forwarding process of frame data between multiple communication channels, the routing method comprising:

retrieving, according to a state of a vehicle, a routing map prepared for an initialization time from a first routing map storing portion in the initialization time when an engine of the vehicle is started;

transmitting the routing map prepared for the initialization time to a hardware search engine to execute a routing using the routing map;

retrieving a routing map prepared for a time of adding a number of the multiple communication channels or a number of entries from the first routing map storing portion in the time when the state of the vehicle is changed and receives a controller'"'"'s add request to increase the number of the communication channels or the number of entries which transmit and receive frame data by using the communication channels;

transmitting the routing map prepared for the time of adding the number of the communication channels or the number of the entries to the hardware search engine to execute a routing using the routing map;

retrieving frame data from a reception storage region in one of reception storage portions;

dividing the frame data into frame data to be sent to the controller and the frame data to be sent to the hardware search engine according to the reception storage region from which the frame data is retrieved, the frame data being divided according to an identification number respectively recorded in the frame data and being respectively stored in the reception storage region in one of the reception storage portions;

executing a routing process by the controller, controlled by software programs, that receives the divided frame data and transmits the frame data to a transmission storage region in one of transmission storage portions prepared for a communication channel being used by an entry to which the frame data is sent;

executing a routing process by the hardware search engine using the routing map prepared for the initialization time or the routing map prepared for the time of adding the number of the communication channels or the number of the entries, that receives the divided frame data and transmits the frame data to a transmission storage region in one of the transmission storage portions prepared for a communication channel being used by an entry to which the frame data is sent, regardless to the routing process by the controller; and

receiving the frame data transmitted from the controller and the frame data transmitted from the hardware search engine, and selecting the frame data to be stored in the transmission storage portions.