The VCU Sync IP core acts as a fence IP between the Video DMA IP and the VCU IP. It is used in Multimedia applications that need ultra-low latencies. The VCU Sync IP does a AXI transaction level tracking so that producer and consumer can be synchronized at the granularity of AXI transactions, instead of granularity of Video Buffer level.
The VCU Sync IP is responsible for synchronizing buffers between the Capture DMA and the VCU encoder. Capture hardware writes video buffers in raster scan order. The VCU Sync IP monitors the buffer level while capture element is writing into DRAM, and allows the encoder to read input buffer data if the requested data is already written by DMA. Otherwise, it blocks the encoder until the DMA completes its writes.
- The VCU Sync IP core can track up to four producer transactions simultaneously
- Each channel can track up to three buffer sets
- Each buffer set has Luma and Chroma buffer features
- Each consumer port can hold 256 AXI transactions without back-pressure to the consumer
- In encoder mode, the Sync IP core supports the tracking and control of four simultaneous channels
For more information, see Chapter 7 of H.264/H.265 Video Codec Unit LogiCORE IP Product Guide (PG252).