Buffering of a data stream

• US 20110320651A1
• Filed: 06/24/2010
• Published: 12/29/2011
• Est. Priority Date: 06/24/2010
• Status: Active Grant

• Current Assignee: Arm Limited (SoftBank Group Corp.)
• Original Assignee: Arm Limited (SoftBank Group Corp.)
• Inventors: Swaine, Andrew Brookfield, Poublan, Serge Henri
• Granted Patent: US 8,499,106 B2
• Time in Patent Office: Days
• US Class Current: 710/53
• CPC Class Codes: G06F 2205/063 Dynamically variable buffer size
• CPC Class Codes: G06F 2205/126 Monitoring of intermediate fill level, i.e. with additional means for monitoring the fill level, e.g. half full flag, almost empty flag
• CPC Class Codes: G06F 5/12 Means for monitoring the fill level; Means for resolving contention, i.e. conflicts between simultaneous enqueue and dequeue operations

Abstract

A data processing apparatus is provided comprising a buffer for buffering data contained in a data stream generated by a data stream generator and received by a data stream receptor. Buffer occupancy tracking circuitry is provided and configured to maintain a high buffer utilisation value providing an indication of a high buffer occupation level for a given time period during utilisation of the buffer. Alternatively, in an apparatus where the buffer is implemented in dedicated memory, the buffer occupancy tracking circuitry is configured to store a programmable buffer size limit controlling a maximum allowable buffer storage capacity.

Claims

1. Apparatus for processing data comprising:

a data stream generator configured to generate a data stream;

a buffer configured to receive said data stream and to buffer data contained in said data stream;

a data stream receptor configured to receive data of said data stream from said buffer;

buffer occupancy tracking circuitry configured to monitor an occupancy level of said buffer resulting from transfer of said data stream between said data stream generator and said data stream receptor and to maintain a highest buffer utilisation value providing an indication of a highest buffer occupation level for a given time period during utilisation of said buffer.

2. Apparatus as claimed in claim 1, wherein said data stream comprises a diagnostic data stream containing diagnostic data for said data processing apparatus.

3. Apparatus as claimed in claim 2, wherein said data stream generator is a trace source and said diagnostic data stream is a trace data stream.

4. Apparatus as claimed in claim 3, wherein said buffer is implemented as a dedicated memory.

5. Apparatus as claimed in claim 3, wherein said data processing apparatus comprises system memory and wherein said buffer is implemented as at least a portion of said system memory.

6. Apparatus as claimed in claim 3, wherein said buffer occupancy tracking circuitry is configured to store a current buffer utilisation value providing an indication of a current buffer utilisation at a current processing cycle.

7. Apparatus as claimed in claim 6, wherein said buffer occupancy tracking circuitry is configured to store a buffer size limit controlling a maximum allowable buffer storage capacity.

8. Apparatus as claimed in claim 7, wherein said buffer size limit is programmable.

9. Apparatus as claimed in claim 8, wherein said buffer is implemented in dedicated memory and wherein buffer size limit is less than a memory capacity of a memory in which said buffer is implemented.

10. Apparatus as claimed in claim 9, wherein said buffer is implemented in a system memory and said buffer monitoring circuitry is configured to perform a comparison between said current buffer occupancy level and said buffer size limit and to dynamically allocate more of said memory capacity to said buffer depending upon a result of said comparison.

11. Apparatus as claimed in claim 3, wherein said highest buffer occupation level is stored in a dedicated register.

12. Apparatus according to claim 3, wherein said highest buffer occupation level is updated for each processing cycle.

13. Apparatus as claimed in claim 3, wherein said data processing apparatus comprises a Field Programmable Gate Array.

14. Apparatus as claimed in claim 1, wherein said data stream receptor is one of a memory, a peripheral, a trace port and a frame buffer.

15. Apparatus as claimed in claim 3, wherein said data stream receptor is configured to store said data stream in a system memory.

16. Apparatus as claimed in claim 3, wherein said data processing apparatus is fabricated on an integrated circuit.

17. Apparatus as claimed in claim 16, wherein said data stream receptor is configured to output in real time said data stream to a device external to said integrated circuit.

18. Apparatus as claimed in claim 17, wherein said buffer occupancy tracking circuitry is configured to store a buffer size limit providing an indication of a maximum allowable buffer storage capacity, said stored buffer size limit being accessible by a device external to said integrated circuit.

19. Apparatus as claimed in claim 17, wherein said buffer occupancy tracking circuitry is configured to store a current buffer utilisation value providing an indication of a current buffer utilisation at a current processing cycle, said stored current buffer utilisation value being readable by said device external to said integrated circuit.

20. Apparatus as claimed in claim 18, wherein said buffer is implemented as a dedicated memory.

21. Apparatus for processing data comprising:

a data stream generator configured to generate a data stream;

a buffer configured to receive said data stream and to buffer data contained in said data stream, said buffer being implemented as a dedicated memory;

a data stream receptor configured to receive data of said data stream from said buffer; and

buffer occupancy tracking circuitry configured to store a programmable buffer size limit controlling a maximum allowable buffer storage capacity.

22. Apparatus as claimed in claim 21, wherein said data stream comprises a diagnostic data stream containing diagnostic data for said data processing apparatus.

23. Apparatus as claimed in claim 22, wherein said data stream generator is a trace source and said diagnostic data stream is a trace data stream.

24. Method for processing data comprising the steps of:

generating a data stream;

receiving said data stream at a buffer and buffering data contained in said data stream;

receiving at a data stream receptor data of said data stream from said buffer;

monitoring an occupancy level of said buffer resulting from transfer of said data stream between said data stream generator and said data stream receptor and for maintaining a highest buffer utilisation value providing an indication of a highest buffer occupation level for a given time period during utilisation of said buffer.

25. Method for processing data, said method comprising the steps of:

generating a data stream using a data stream generator;

receiving at a buffer said data stream and buffering data contained in said data stream, said buffer being implemented as a dedicated memory;

receiving at a data stream receptor, data of said data stream from said buffer; and

storing a programmable buffer size limit controlling a maximum allowable buffer storage capacity.

26. Apparatus for processing data comprising:

means for generating a data stream;

means for receiving said data stream at a buffer and buffering data contained in said data stream;

further means for receiving said data stream on output from said buffer;

means for monitoring an occupancy level of said buffer resulting from transfer of said data stream between said means for generating and said further means for receiving and for maintaining a highest buffer utilisation value providing an indication of a highest buffer occupation level for a given time period during utilisation of said buffer.

27. Apparatus for processing data comprising:

means for generating a data stream;

means for receiving at a buffer said data stream and buffering data contained in said data stream, said buffer being implemented as a dedicated memory;

further means for receiving data of said data stream on output from said buffer; and

means for storing a programmable buffer size limit controlling a maximum allowable buffer storage capacity.