The Display Subsystem (DSS) is a flexible
composition-enabled display subsystem that supports multiple high resolution display
outputs. It consists of the following main modules:
- Display Controller (DISPC),
with the following main features:
- Support of
multi-layer blending and transparency for each of display
outputs
- Supports write-back
pipeline with scaling to enable memory-to-memory composition and/or
to capture a display output for Ethernet video encoding
- Supports gamma
correction and programmable color control in both source and
destination pipelines
- Embedded DMA
Controller with the following main features:
- Support for
1D-only DMA transfers
- Support for
48b addressable memory space
- Support for
memory fragmentation through external PAT at SoC level
- Integrated
shared buffer management for pipelines within the same DMA
controller group
- Programmable
DMA requests management
- Support for
source image flip along X and Y-axis
- Support for
secure access to firewall protected frame buffer in DDR
memory
- Two input display
processing Video Pipelines, each supporting:
- Wide range of
input RGB source pixel formats
- Wide range of
input YUV source pixel formats
- Programmable
poly-phase filter (scaler)
- Programmable
color space conversion
- Programmable
Brightness/Contrast/Hue/Saturation
- Programmable
Gamma Correction LUT
- Luma Key
generation
- 10-bit
processing pipeline
- Two input display
processing Video Lite Pipelines, each supporting:
- Wide range of
input RGB source pixel formats
- Wide range of
input YUV source pixel formats
- YUV420 to
YUV422 chroma up-sampling using an average filter
- YUV422 to
YUV444 chroma up-sampling using a 4-tap filter based on
Catmull-Rom algorithm
- Programmable
color space conversion
- Programmable
Brightness/Contrast/Hue/Saturation
- Programmable
Gamma Correction LUT
- Luma Key
generation
- 10-bit
processing pipeline
- One Write-back (WB)
pipeline, supporting:
- Wide range of
destination RGB pixel formats
- Wide range of
destination YUV pixel formats
- Programmable
poly-phase filter (scaler)
- Output
capture and Memory-to-memory (M2M) operation modes
- Four Overlay Managers
(OVR), each supporting:
- Input pixel
format: ARGB48-12121212
- Output pixel
format: ARGB48-12121212
- Overlay of
the input pipelines
- Up to 5 input
layers blending
- Transparency
color key
- Alpha
blending support: Embedded pixel alpha (ARGB and RGBA),
global pixel, and combination of global pixel and pixel
alpha
- Z-order
programmable (full flexibility)
- Color bar
test pattern insertion
- Any overlay
output can be selected to drive the Write-back pipeline
- Four Video Port (VP)
display outputs, each supporting:
- 36-bit per
pixel on the RGB output interface
- Independent
programmable timing generator, supporting up to 600 MHz
pixel clock video formats
- Independent
programmable 10-bit gamma correction
- Independent
programmable multiple cycles output format on 8/9/12/16-bit
interface
- Selection
between RGB and YUV422 output pixel
- Configurable
VP output mode
- Internal diagnostic
features:
- Supports up
to 4 programmable (position/size) check regions on the DISPC
video port display outputs
- Support for 1
check region on each input video pipeline output
- MISR
(Multiple Input Signature Register) used on each check
region to perform data correctness check and/or freeze frame
detection
- Local power features:
- Low power
saving modes
- On-the-fly
Dynamic Frequency Scaling (DFS) support
- Capability to
associate all buffers a single pipeline for a display
self-refresh
- System interconnect
ports:
- Two 128-bit
VBUSM master interfaces for data read/write
- One 32-bit
VBUSP slave interface for configuration
- Fram Buffer Decompression Core (FBDC), that performs a
decompression on lossless compressed images on a tile-by-tile basis.
- MIPI Display Serial Interface
(DSI) transmitter host controller, with the following main features:
- Compliance with MIPI
DSI 1.3.1 and previous protocol specifications
- Compliance with
Stereoscopic Display Format (SDF) specification
- Video and command
operational modes
- Both burst and
non-burst modes for video mode data transmission
- Up to 4 virtual
channels via command mode
- Bi-directional
communication and escape mode
- Pixel clock rate
range: 25-330 MHz
- Programmable display
resolutions
- 16/18/24/30/36-bit
RGB input data formats for video mode
- RGB16, RGB18 packed,
and RGB24 input data formats for command mode
- All generic data
types defined by MIPI
- Display Command Set
(DCS) transparent to the protocol engine
- ECC on the APB
interface
- Data splitter for
2-,3-, or 4-data lane configuration
- Connection to a
single MIPI D-PHY complex I/O through an 8-bit Protocol Peripheral
Interface (PPI)
- Tearing effect (TE)
input signals for command mode display
- Bus contention
recovery
- Video mode pattern
generator: color bar pattern image and D-PHY BET testing
pattern
- APB slave interface
with 32-bit data and address for configuration
- The MIPI DSI Physical Layer
(D-PHY) module with the following main features:
- Compliance with MIPI
D-PHY 1.2 physical layer interface specification and features
- 1, 2 or 4 data lanes,
in addition to clock signaling
- Maximum data rate up
to 2.5 Gbps per data lane
- Protocol Peripheral
Interface (PPI)
- HS continuous and
burst mode
- Low-Power (LP),
Ultra-Lower Power Mode (ULPM), and Shutdown modes
- Forward direction and
reverse direction escape modes
- Automatic termination
control in both high-speed and low-power modes
- Single 32-bit VBUSP
slave interface
- Embedded DisplayPort (eDP)
transmitter host controller with the following main features:
- Compliance with VESA®DisplayPort™
(DP) 1.3 (with 1.4 DSC/FEC support) specification
- Compliance with VESA
Embedded DisplayPort (eDP) 1.4 specification
- Static configuration
of either DP or eDP mode
- Link rates up to High
Bit Rate 3 (HBR3)
- Pixel clock rate
range: 25-600 MHz
- 8, 10, and 12 bpc
(bits per component), in RGB/YCbCr444 colorimetry formats (CEA-861
compliant) and YCbCr422 (via simple decimation)
- Data splitter for 1-,
2-, or 4-data lane configuration
- Single Stream
Transport (SST)
- Multiple Stream
Transport (MST)
- High-bandwidth
Digital Content Protection (HDCP) data encryption via an embedded
HDCP core
- Display Stream
Compression (DSC) encoded stream data transport via an embedded DSC
core
- Forward Error
Correction (FEC) encoder with/without DSC enabled in DP mode
- Single Stream
Transport (SST)
- Audio transport
features
- Metadata transport
via Main Stream Attribute (MSA) packet or via SDP
- APB slave ports for
TX/PHY controller configuration
- SAPB (secure) slave
port for secure connection
- Video source muxing
options
- One 32-bit VBUSP
slave interface used for configuration
- ECC on the critical
memories
- Parity check on the
configuration interface
- Encoder self-check
diagnostics support in the DSC core
- Injection of ECC and
parity errors
- eDP (Physical Layer) SERDES
and Aux PHY modules with the following main features:
- DP1.3, HBR3 and
eDP1.4a HBR3 throughput
- 1, 2, or 4 lanes at
1.62Gbps, 2.7Gbps, 5.4Gbps, and 8.1Gbps per lane
- Additional link rates
(2.16, 2.43, 3.24, 4.32Gbps) per lane in eDP mode
- Reduced differential
voltage swing (0.2/0.25/0.30/0.35/0.40/0.45) in eDP mode
- Hot Plug Detect (HPD)
for connection detection and interrupt from sink
- Integrated Low
Jitter, Fixed Bandwidth PLL
- DisplayPort physical
layer functionalities:
- Scrambler
- 8/10-bit
encoder (within the eDP transmitter)
- Inter Lane
Skew Insertion
- Training
Pattern Generation – TPS1,2,3,4 PRBS7 and 80-bit custom
training pattern generation (bypassing the scrambler and
encoder)
- 1 Mbps AUX PHY for link
training, DPCD register access, HDCP authentication and EDID access