SPRUIE9D May 2017 – May 2024 DRA74P , DRA75P , DRA76P , DRA77P
VPDMA is used to configure the coefficient memories of scaler through VPI control interface. Since the coefficient memories are not shadowed (unlike the memory mapped registers), VPI control write access needs to be done only during the gap between video frame processing times. If a write request is made while the Scaler is active, the access will be held off by the hardware until the last data of the currently processed frame is sent out. Care must be given to the order of the DMA descriptors so that blocking of VPI control bus does not occur.