Two dimensional memory caching apparatus for high definition video
View Patent ↗A computer readable medium is provided embodying instructions executable by a processor to perform a method for caching video data in a two-dimensional cache. The method includes storing the video data in the two-dimensional cache, addressing stored video data in the two-dimensional cache using a first tag for referencing video data of a first dimension, addressing the stored video data in the cache in terms of a second tag for referencing video data of a second dimension, and retrieving and outputting a portion of the stored video data from the two-dimensional cache according to one of the first tag and the second tag.
1. A non-transitory computer-readable media embodying instructions executed by a processor to perform a method for caching video data in a two-dimensional cache, the method comprising:
storing the video data in a plurality of banks of the two-dimensional cache having a y-axis component and an x-axis component;
controlling a bank select to retrieve a portion of the stored video data from the plurality of banks of the two-dimensional cache according to a comparison of a first tag and a second tag of an address to a plurality of tags stored in a set associative cache comprising a plurality of sets corresponding to the plurality of banks, respectively,
wherein the plurality of tags correspond to the video data stored in the plurality of banks,
the first tag of the address for referencing a first dimension of the two-dimensional cache corresponding to the y-axis component, and the second tag of the address for referencing a second dimension of the two-dimensional cache corresponding to the x-axis component; and
outputting the portion of the stored video data from the two-dimensional cache according to the comparison,
wherein a field size of the first tag and a field size of the second tag vary depending upon a resolution of the video data.
2. The non-transitory computer-readable media of claim 1 , wherein the video data is parsed according to the vertical and horizontal resolution of the video data.
3. The non-transitory computer-readable media of claim 1 , wherein the address is a 25-bit address, the 25-bit address comprising:
the first tag of 10-bits;
a set index of 4-bits;
the second tag of 4-bits; and
a line byte address of 7-bits.
4. The non-transitory computer-readable media of claim 1 , wherein the field size of the second tag is set proportionally to the horizontal resolution of the video data.
5. The non-transitory computer-readable media of claim 1 , wherein the video data is addressed by the address comprising:
the first tag;
a set index;
the second tag; and
a line byte address.
6. The non-transitory computer-readable media of claim 5 , wherein a value of the second tag in conjunction with a value of the line byte address represents the x-axis component of the video data and a value of the first tag in conjunction with a value of the set index represents the y-axis component of the video data.
7. A two-dimensional cache for storing video data that has been decompressed from an H.264 video compression standard, comprising:
a plurality of two-dimensional addresses for storing tags of cached video data, each two-dimensional address comprising a first tag for referencing video data of a first dimension and a second tag for referencing video data of a second dimension;
a plurality of banks for storing the cached video data of the first and second dimensions;
a plurality of comparators for identifying cache bits of the cached video data stored in a plurality of sets corresponding to the plurality of banks, respectively, according to the first tag and the second tag; and
a bank select for retrieving the cached video data,
wherein a field size of the first tag and a field size of the second tag vary depending upon a resolution of the video data.
8. The cache of claim 7 , wherein the cache is a set-associative cache.
9. The cache of claim 7 , wherein the cache is a 4-way set-associative cache.
10. The cache of claim 7 , wherein the video data is parsed according to the vertical and horizontal resolution of the video data.
11. The cache of claim 7 , wherein each two-dimensional address comprises:
the first tag;
a set index;
the second tag; and
a line byte address.
12. The cache of claim 7 , wherein a value of the second tag in conjunction with a value of the line byte address represents an x-axis of the video data and a value of the first tag in conjunction with a value of the set index represents a y-axis of the video data.
13. The cache of claim 7 , wherein the field size of the second tag is set proportionally to the horizontal resolution of the video data.