The Davinci Effect

DaVinci technology offers the right processors for digital video applications, combining digital signal processing and video accelerator technology. The DM643x processors based on DaVinci technology provide all of the processing capacity required to handle multiple functions on a single chip, and these processors are integrated with all of the peripherals necessary for a complete video/imaging processing system. As a result, developers don’t need to spend valuable time getting multiple components to work together as they have already been integrated.

For example, the TMS320DM6437 processor provides a powerful video front-end to handle key preprocessing functionality. A video back-end is also provided so that processed images can be displayed, such as for rear-view parking assist and night vision applications. From a peripheral perspective, three of the DM643x devices have an integrated high-end CAN controller, and SPI and UART peripherals, enabling it to tie into CAN or LIN bus of any automotive system. DDR2 memory support provides higher throughput to maximize system performance.

DM643x processors also provide specialized functionality optimized for active safety and ADAS applications. The video port front-end, for example, has several preprocessing blocks which can offload processing from the main processor, enabling more value-added active safety functions to be implemented on a single DSP. Specifically, the front-end offers a resizer block which can upscale and downscale an image to an appropriate resolution without using CPU cycles. The resizer block can free the CPU cycles when a section of an image (region of interest) needs to be normalized to a predefined size.

The TMS320DM643x processor video port front-end supports BT656, YCrCb, or Bayer format. The video port front-end on the TMS320DM6435 and TMS320DM6437 processors also offers a histogram function which provides distribution of pixel intensities of the captured frame. Using information from the histogram, the DSP can adjust the contrast to improve recognition accuracy. The video port front-end is also capable of conversion from Bayer to YCrCrb color space freeing up the TMS320C64x+ DSP core to perform other tasks.

Video processing involves large blocks of data. Processors have limited on-chip memory resources, so these must be managed carefully to minimize overall latency, especially when multiple algorithms are operating in parallel and sharing available resources.

Developers can ease the burden on memory resources by focusing on areas of interest and with the use of a fast L2 cache and enhanced DMA (EDMA). By using EDMA to preload the internal memory before data is needed, overhead of the CPU accesses to external memory can be reduced.

The DM643x processor EDMA v3.0 is capable of performing three-dimensional data transfers. The ports on predecessor EDMA v2.0 were limited to only two-dimensional transfers. Two-dimensional DMA transfer is sufficient when only one section of the image needs to be transferred from source to destination memory. In case multiple regions of the image need to be moved around support for the third DMA dimension is essential. Therefore, three dimensional transfers are useful when multiple regions-of-interest need to be transferred between external and on-chip memory that directly translates to higher efficiency.