Contiguously packed data

• US 20090157963A1
• Filed: 12/17/2007
• Published: 06/18/2009
• Est. Priority Date: 12/17/2007
• Status: Active Grant

• Current Assignee: NVIDIA Corporation
• Original Assignee: NVIDIA Corporation
• Inventors: Mills, Christopher L., Mahan, Justin Michael, Toksvig, Michael J.M.
• Granted Patent: US 8,780,128 B2
• Time in Patent Office: Days
• US Class Current: 711/118
• CPC Class Codes: G06F 12/04 Addressing variable-length words or parts of words
• CPC Class Codes: G06F 12/0886 Variable-length word access
• CPC Class Codes: G06T 1/60 Memory management

Abstract

Data for data elements (e.g., pixels) can be stored in an addressable storage unit that can store a number of bits that is not a whole number multiple of the number of bits of data per data element. Similarly, a number of the data elements can be transferred per unit of time over a bus, where the width of the bus is not a whole number multiple of the number of bits of data per data element. Data for none of the data elements is stored in more than one of the storage units or transferred in more than one unit of time. Also, data for multiple data elements is packaged contiguously in the storage unit or across the width of the bus.

Claims

1. A computer-implemented method of managing data, said method comprising:

accessing data for a plurality of discrete data elements, wherein each of said data elements comprises a first number of bits of data; and

storing said data in a memory comprising a plurality of addressable storage units, each of said storage units comprising a contiguous segment of a second number of bits that is not a whole number multiple of said first number of bits, wherein data for none of said data elements is stored in more than one of said storage units, and wherein data for multiple data elements is stored contiguously in an addressable storage unit.

2. The method of claim 1 wherein five 24-bit data elements are stored every 16 bytes in said memory.

3. The method of claim 1 wherein ten 24-bit data elements are stored every 32 bytes in said memory.

4. The method of claim 1 wherein 21 24-bit data elements are stored every 64 bytes in said memory.

5. The method of claim 1 wherein 85 24-bit data elements are stored every 256 bytes in said memory.

6. The method of claim 1 wherein N K-byte data elements are contiguously stored every M bytes in said memory, where K and N are whole numbers, where K*N is less than M and where M is not a whole number multiplier of K.

7. A computer-implemented method of managing data, said method comprising:

accessing data for a plurality of discrete data elements, wherein each of said data elements comprises a first number of bits of data; and

storing said data in a cache comprising a plurality of cache lines, each of said cache lines capable of storing a second number of bits that is not a whole number multiple of said first number of bits, wherein data for none of said data elements is stored in more than one of said cache lines, and wherein data for multiple data elements is stored contiguously in a cache line.

8. The method of claim 7 wherein five 24-bit data elements are stored every 16 bytes in a cache line.

9. The method of claim 7 wherein ten 24-bit data elements are stored every 32 bytes in a cache line.

10. The method of claim 7 wherein 21 24-bit data elements are stored every 64 bytes in a cache line.

11. The method of claim 7 wherein 85 24-bit data elements are stored every 256 bytes in a cache line.

12. The method of claim 7 wherein N K-byte data elements are contiguously stored every M bytes in a cache line, where K and N are whole numbers, where K*N is less than M and where M is not a whole number multiplier of K.

13. The method of claim 7 further comprising retrieving data for a selected data element from said cache by computing a location for said selected data element, said location computed by:

i) dividing a number associated with said selected data element by the maximum number of data elements that can be stored contiguously in a segment of bits to determine a floor and a remainder, ii) multiplying said floor by the number of bytes in said segment to determine a first result, iii) multiplying said remainder by the number of bytes per data element to determine a second result, and iv) adding said first and second results.

14. A computer-implemented method of managing data, said method comprising:

accessing data for a plurality of discrete data elements, wherein each of said data elements comprises a first number of bits of data; and

transferring a number of said data elements per unit of time over a bus, wherein said bus is capable of transferring a second number of bits per said unit of time, wherein said second number is not a whole number multiple of said first number of bits, wherein data for none of said data elements is transferred in more than one said unit of time, and wherein data for multiple data elements is packaged contiguously in said bus.

15. The method of claim 14 wherein each of said data elements comprises 24 bits of data and wherein said bus is 16 bytes in width.

16. The method of claim 14 wherein five 24-bit data elements are packaged contiguously across the width of said bus.

17. The method of claim 14 wherein ten 24-bit data elements are packaged contiguously across the width of said bus.

18. The method of claim 14 wherein 21 24-bit data elements are packaged contiguously across the width of said bus.

19. The method of claim 14 wherein 85 24-bit data elements are packaged contiguously across the width of said bus.

20. The method of claim 14 wherein N K-byte data elements are contiguously stored every M bytes in of bus width, where K and N are whole numbers, where K*N is less than M and where M is not a whole number multiplier of K.