SPRUJ28E November 2021 – September 2024 AM68 , AM68A , TDA4AL-Q1 , TDA4VE-Q1 , TDA4VL-Q1
The DSS exports the VSYNC, HSYNC and DE signals of all DISPC video port outputs to the SoC boundary. This feature is supplementary to the signals already exported out on the parallel DPI interfaces (DPI0/DPI1). This allows the support of the following use cases:
The necessary singnal muxing is achieved at SoC level (via I/O pin multiplexing).
BT.601 Standard Support
The DSS only supports YUV output with embedded syncs (BT.656 and BT.1120 standards). YUV output with discrete sync (BT.601 standard) is not supported natively on the DISPC VP outputs.
At SoC level, it is possible to achieve BT.601 operation on a DPI parallel out (DPI0/DPI1) by combining two DISPC VP outputs as follows:
FSYNC Support for External Camera Sensor
An external camera sensors can use the VSYNC output from DSS as a synchronization input (FSYNC input). To make this connection, the VSYNC signals of all DISPC video ports are made available at SoC boundary.
Generally, in the cases where the DISPC VP is connected to DSI or eDP, the VSYNC information is "lost" as a separate signal at SoC boundary, although this VSYNC is still available at DISPC module boundary. For such cases, the VSYNCs are exported to SoC level in parallel to the DSI/eDP connection.