SPRUJ28E November 2021 – September 2024 AM68 , AM68A , TDA4AL-Q1 , TDA4VE-Q1 , TDA4VL-Q1
Circular buffer feature enables other VPAC HWAs feeding data directly to LDC. In this case, input data to LDC is stored on-chip to save BW primarily and latency from DDR. However, in some use cases, on-chip memory allocation won’t be sufficient to store required circular buffer. By storing extreme distortion regions in DDR, on-chip circular buffer size requirement can be reduced. This requires hybrid addressing support where some part of image is stored in linear addressing buffer and rest is stored in circular buffer. Hybrid addressing can be enabled by setting CTRL.HYBD_ADDREN. Programmable initial and end range of the image can be stored in linear addressing buffers. Start line of circular buffer is configured by HYBD_CBUFF_PARAM.STARTLINE and End line by HYBD_CBUFF_PARAM.ENDLINE. Image outside of this range is stored in 2 separate linear buffers.
Linear buffers can be stored in independent addresses and each buffer has separate base address. Circular buffer enable should be set when hybrid addressing is enabled.