SPRUIE9D May 2017 – May 2024 DRA74P , DRA75P , DRA76P , DRA77P
The RSZ module includes two write-only MTC interfaces. Their implementation enables passing a maximum of eight 32-byte requests in 10 clock cycles. The RSZ must be programmed to obtain smooth and average bandwidth to buffer logic module by setting a minimum interval between two successive requests (set the RSZ_DMA_RZA[15:0] RZA and RSZ_DMA_RZB[15:0] RZB bit fields for the A and B resizers as appropriate). This setting is not expected to be dynamic. It can be a fixed setting from request to request and frame to frame. When the bandwidth is set appropriately, between the first valid translated pixel and the EOF signal sent to buffer logic, the RSZ_DMA_STA[0] STATUS bit can be seen, and it is high if the transfer over the MTC interfaces is active. Figure 9-93 shows how RSZ_DMA_RZx for resizers A and B affects the MTC data request generator.
Figure 9-94 shows the pixel order in memory written by the MTC. The arrows do not represent the order in which data is written. Data are always written from left to right, whether horizontal reversal is enabled or not.
The RSZ MTC interfaces can be stalled by the input MTC STALL signal. The assertion of the MTC STALL signal is a result of a hardware mechanism that monitors the CBUFF module to prevent its overflow. When this signal is asserted, the current 32-byte MTC request is finished and then the RSZ MTC output ports are stalled. For further details on the output ports, see Section 9.3.3.6.6.7, ISS ISP RSZ Output Interface.