DATA PROCESSING APPARATUS USING RING BUS, DATA PROCESSING METHOD ANDCOMPUTER-READABLE STORAGE MEDIUM

• US 20100303090A1
• Filed: 05/25/2010
• Published: 12/02/2010
• Est. Priority Date: 05/29/2009
• Status: Abandoned Application

• Current Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Original Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Inventors: Ishikawa, Hisashi, Inoue, Hirowo
• Application Number:
  US12/787,248
• Publication Number:
  US 20100303090A1
• Time in Patent Office: Days
• US Class Current: 370/401
• CPC Class Codes: H04L 12/42 Loop networks

Abstract

In an apparatus connected to a ring bus, deadlocks and degradation in effective efficiency of the ring bus could occur when a plurality of data processing streams are input or a case when the amount of data inside a processing circuit increases/decreases is present. To solve this, degradation in processing efficiency is minimized by making a working speed of the ring bus faster than the working speed necessary for data processing to reduce occasions for suppression of data output by data moving around the ring bus.

Claims

1. An apparatus in which a plurality of modules are connected in a ring shape via a bus and the modules process data while transferring a packet in a ring in one direction, each of the module comprising:

a processing unit configured to process and output data stored in the packet;

a transmitting unit configured to transmit the packet to the module on a downstream side; and

a control unit configured to control the transmitting unit so that when the processing unit requires a predetermined length of processing time before one packet is processed and output, the transmitting unit transmits a plurality of packets in the predetermined length.

2. The apparatus according to claim 1, wherein the control unit controls the transmitting unit so that one packet can be transmitted in the length of time or less of a greatest common divisor of processing times of the plurality of modules for each the predetermined length of the plurality of the modules.

3. The apparatus according to claim 1, the module further comprising a setting unit configured to set an ID of the packet to be processed to the processing module according to content of pipeline processing performed by the plurality of processing units.

4. The apparatus according to claim 1, the module further comprising:

a register configured to store an ID of the packet to be processed; and

a receiving unit configured to transfer, to the processing unit, the data stored in the packet whose ID and the ID of the packet to be processed match.

5. The apparatus according to claim 4, wherein the receiving unit allows the packet whose ID and the ID of the packet to be processed do not match to pass to the bus directly.

6. The apparatus according to claim 1, further comprising:

an input unit configured to input the data into the bus in the ring shape.

7. The apparatus according to claim 1, further comprising:

an output unit configured to output the packet to an external unit according to an ID of the input packet.

8. The apparatus according to claim 1, wherein the transmitting unit further includes a register that stores an ID specific to the transmitting unit and transmits the packet storing the data processed and the specific ID to the bus.

9. The apparatus according to claim 1, wherein if an ID of the packet and the ID of the packet to be processed match and the processing unit is not ready to receive the data, the transmitting unit transfers the packet after stall information is added thereto.

13. The apparatus according to claim 1, wherein the packet includes information indicating whether the stored data is valid, information indicating whether the packet is in a stalled state, and information indicating an ID of the module that output last and an order of input into the bus.

14. The apparatus according to claim 1, the module further comprising:

a data holding unit connected to the bus; and

a change unit configured to change a number of stages of the data holding unit.

15. The apparatus according to claim 1, the module further comprising

a speed control unit configured to control a speed of at least one of the transmitting unit and the processing unit.

16. The apparatus according to claim 15, wherein if a number of stages effectively operating among data holding units each inserted between individual modules connected to the bus is N, and the number of stages effectively operating among data holding units connected to the bus is M, the speed control unit performs control so that the speed of the transmitting unit is an integral multiple of (N+M) of the speed of the processing unit.

17. The apparatus according to claim 16, wherein if the total number of the data holding units connected to the bus and operating effectively is K, and the total number of the processing units operating effectively is L, the speed control unit performs control so that the speed of the transmitting unit is (K/L) times the speed of the processing unit.

10. An apparatus in which a plurality of modules are connected to a ring bus and the plurality of modules performs data processing in a preset order, each of the modules comprising:

a holding unit configured to hold received data for a predetermined time; and

a transmitting unit configured to transmit the held data to another module.

11. An apparatus in which a plurality of modules are connected to a ring bus and the plurality of modules performs data processing in a preset order, each of the modules comprising:

a communication unit configured to transmit/receive data in a ring bus and a processing unit configured to perform processing of received data;

an input FIFO that temporarily holds the received data, an output FIFO that temporarily holds output data processed by the processing unit;

a processing-through unit configured to transmit the data from the input FIFO to the output FIFO without going through the processing unit; and

a switching unit configured to switch an operation of the processing-through unit between the communication unit and the processing unit.

12. The apparatus according to claim 11, wherein if a total number of data holding units operating effectively in the ring bus is K, the total number of the processing units effectively operating is L, and the number of data processing streams input into the ring bus at the same time is S,

the switching unit switches the processing-through unit so that K≧

L×

S is satisfied.

18. A method for an apparatus in which a plurality of modules are connected in a ring shape via a bus and the modules process data while transferring a packet in a ring in one direction, comprising:

processing the data stored in the packet;

transmitting the packet to a downstream side; and

performing control so that during one packet being processed and output, a plurality of packets is transmitted.

19. A non-transitory computer-readable storage medium storing a program that controls an apparatus in which a plurality of modules are connected in a ring shape via a bus and the modules process data while transferring a packet in a ring in one direction, the program causing a computer to function as:

a processing unit configured to process and output the data stored in the packet;

a transmitting unit configured to transmit the packet to the module on a downstream side; and

a control unit configured to control the transmitting unit so that while the processing unit processes and outputs one packet, the transmitting unit transmits a plurality of packets.