This Figure shows a video system that includes live-external video (peak) bandwidth and memory (average) bandwidth requirements.
In This Figure , 720p live video frames are written to external memory with a bandwidth of 1.19 Gb/s. These frames can be read at an average bandwidth of 0.88 Gb/s. These frames are then downscaled and written at an average bandwidth of 0.29 Gb/s. The downscaled frames can then be read from external memory at a peak bandwidth of 0.40 Gb/s to display to external video.
Thus, video input bandwidth is BW peak of input size. Video output bandwidth is BW peak of output size. Intermediate memory read bandwidth is B Wave of input size. Intermediate memory write bandwidth is B Wave of output size.
|
|
Video Input (Memory Write) |
Memory Read |
Memory Write |
Memory Read (Video Output) |
Total/Maximum |
|---|---|---|---|---|---|
|
Minimum Frequency |
74.25 MHz |
55.3 MHz |
18.43 MHz |
25.20 MHz |
74.25 MHz (Max) |
|
Minimum Bandwidth |
1.19 Gb/s |
0.88 Gb/s |
0.29 Gb/s |
0.40 Gb/s |
2.76 Gb/s (Sum) 1.48 Gb/s (W) 1.28 Gb/s (R) |