6.10.2 DSS
The Display Subsystem (DSS) provides the logic to interface display peripherals. DSS integrates a DMA engine as part of DISPC module, which allows direct access to the memory frame buffer. Various pixel processing capabilities are supported, such as: color space conversion, filtering, scaling, blending, color keying, etc.
The supported display interfaces are:
- One parallel CMOS output, which can be used for MIPI® DPI 2.0, or BT-656 or BT-1120.
- One TV output, which is connected to the internal Video Encoder module (VENC). The VENC drives a single video digital-to-analog converter (SD_DAC) supporting composite video mode.
The modules integrated in the display subsystem are:
- Display controller (DISPC), with the following main features
- One direct memory access (DMA) engine
- One graphics pipeline (GFX), two video pipelines (VID1 and VID2), and one write-back pipeline (WB)
- Two overlay managers
- Active Matrix color support for 12/16/18/24-bit (truncated or dithered encoded pixel values)
- One Video Port (VP) with programmable timing generator to support:
- DPI: up to 165 MHz pixel clock video formats defined in CEA-861-E and VESA DMT standards
- VENC: NTSC/PAL standards with 60Hz/50Hz refresh rates
- Supported maximum FrameBuffer width of 4096 for all pixel formats
- Configurable output mode: progressive or interlaced
- Selection between RGB and YUV422 output pixel formats (YUV4:2:2 only available when BT-656 or BT-1120 output mode is enabled)
For more information, see section Display Controller in chapter Display Subsystem of the device TRM.
- Video Encoder (VENC) with 10-bit standard definition video DAC (SD_DAC).
For more information, see section Video Encoder in chapter Display Subsystem of the device TRM.
DSS provides two interfaces to L3_MAIN interconnect
- One 128-bit master port (with MFLAG support). The DMA engine in DISPC uses this single master to read/write data from/to device system memory.
- One 32-bit slave port. Used for registers configuration. It is further connected internally to DISPC and VENC modules.
For more information, see chapter Display Subsystem of the device TRM.