SNLS477D October   2014  – February 2022 DS90UB948-Q1

PRODUCTION DATA  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
  4. 4 Revision History
  5. 5 Pin Configuration and Functions
  6. 6 Specifications
    1. 6.1  Absolute Maximum Ratings
    2. 6.2  ESD Ratings
    3. 6.3  Recommended Operating Conditions
    4. 6.4  Thermal Information
    5. 6.5  DC Electrical Characteristics
    6. 6.6  AC Electrical Characteristics
    7. 6.7  Timing Requirements for the Serial Control Bus
    8. 6.8  Switching Characteristics
    9. 6.9  Timing Diagrams and Test Circuits
    10. 6.10 Typical Characteristics
  7. 7 Detailed Description
    1. 7.1 Overview
    2. 7.2 Functional Block Diagram
    3. 7.3 Feature Description
      1. 7.3.1  High-Speed Forward Channel Data Transfer
      2. 7.3.2  Low-Speed Back Channel Data Transfer
      3. 7.3.3  FPD-Link III Port Register Access
      4. 7.3.4  Oscillator Output
      5. 7.3.5  Clock and Output Status
      6. 7.3.6  LVCMOS VDDIO Option
      7. 7.3.7  Power Down (PDB)
      8. 7.3.8  Interrupt Pin — Functional Description and Usage (INTB_IN)
      9. 7.3.9  General-Purpose I/O (GPIO)
        1. 7.3.9.1 GPIO[3:0] and D_GPIO[3:0] Configuration
        2. 7.3.9.2 Back Channel Configuration
        3. 7.3.9.3 GPIO Register Configuration
      10. 7.3.10 SPI Communication
        1. 7.3.10.1 SPI Mode Configuration
        2. 7.3.10.2 Forward Channel SPI Operation
        3. 7.3.10.3 Reverse Channel SPI Operation
      11. 7.3.11 Backward Compatibility
      12. 7.3.12 Adaptive Equalizer
        1. 7.3.12.1 Transmission Distance
        2. 7.3.12.2 Adaptive Equalizer Algorithm
        3. 7.3.12.3 AEQ Settings
          1. 7.3.12.3.1 AEQ Start-Up and Initialization
          2. 7.3.12.3.2 AEQ Range
          3. 7.3.12.3.3 AEQ Timing
      13. 7.3.13 I2S Audio Interface
        1. 7.3.13.1 I2S Transport Modes
        2. 7.3.13.2 I2S Repeater
        3. 7.3.13.3 I2S Jitter Cleaning
        4. 7.3.13.4 MCLK
      14. 7.3.14 Repeater
        1. 7.3.14.1 Repeater Configuration
        2. 7.3.14.2 Repeater Connections
          1. 7.3.14.2.1 Repeater Fan-Out Electrical Requirements
      15. 7.3.15 Built-In Self Test (BIST)
        1. 7.3.15.1 BIST Configuration and Status
          1. 7.3.15.1.1 Sample BIST Sequence
        2. 7.3.15.2 Forward Channel and Back Channel Error Checking
      16. 7.3.16 Internal Pattern Generation
    4. 7.4 Device Functional Modes
      1. 7.4.1 Configuration Select MODE_SEL[1:0]
        1. 7.4.1.1 1-Lane FPD-Link III Input, Single Link OpenLDI Output
        2. 7.4.1.2 1-Lane FPD-Link III Input, Dual Link OpenLDI Output
        3. 7.4.1.3 2-Lane FPD-Link III Input, Dual Link OpenLDI Output
        4. 7.4.1.4 2-Lane FPD-Link III Input, Single Link OpenLDI Output
        5. 7.4.1.5 1-Lane FPD-Link III Input, Single Link OpenLDI Output (Replicate)
      2. 7.4.2 MODE_SEL[1:0]
        1. 7.4.2.1 Dual Swap
      3. 7.4.3 OpenLDI Output Frame and Color Bit Mapping Select
    5. 7.5 Image Enhancement Features
      1. 7.5.1 White Balance
      2. 7.5.2 LUT Contents
      3. 7.5.3 Enabling White Balance
        1. 7.5.3.1 LUT Programming Example
      4. 7.5.4 Adaptive Hi-FRC Dithering
    6. 7.6 Programming
      1. 7.6.1 Serial Control Bus
      2. 7.6.2 Multi-Controller Arbitration Support
      3. 7.6.3 I2C Restrictions on Multi-Controller Operation
      4. 7.6.4 Multi-Controller Access to Device Registers for Newer FPD-Link III Devices
      5. 7.6.5 Multi-Controller Access to Device Registers for Older FPD-Link III Devices
      6. 7.6.6 Restrictions on Control Channel Direction for Multi-Controller Operation
    7. 7.7 Register Maps
      1. 7.7.1 DS90UB948-Q1 Registers
  8. 8 Application and Implementation
    1. 8.1 Application Information
    2. 8.2 Typical Applications
      1. 8.2.1 Design Requirements
      2. 8.2.2 Detailed Design Procedure
        1. 8.2.2.1 FPD-Link III Interconnect Guidelines
        2. 8.2.2.2 AV Mute Prevention
        3. 8.2.2.3 Prevention of I2C Errors During Abrupt System Faults
      3. 8.2.3 Application Curves
  9. 9 Power Supply Recommendations
    1. 9.1 Power-Up Requirements and PDB Pin
    2. 9.2 Power Sequence
  10. 10Layout
    1. 10.1 Layout Guidelines
    2. 10.2 Ground
    3. 10.3 Routing FPD-Link III Signal Traces
    4. 10.4 Layout Example
  11. 11Device and Documentation Support
    1. 11.1 Documentation Support
      1. 11.1.1 Related Documentation
    2. 11.2 Receiving Notification of Documentation Updates
    3. 11.3 Support Resources
    4. 11.4 Trademarks
    5. 11.5 Electrostatic Discharge Caution
    6. 11.6 Glossary
  12. 12Mechanical, Packaging, and Orderable Information

Package Options

Mechanical Data (Package|Pins)
Thermal pad, mechanical data (Package|Pins)
Orderable Information

7.3.9.2 Back Channel Configuration

The D_GPIO[3:0] pins can be configured to obtain different sampling rates depending on the mode as well as back channel frequency. The mode is controlled by register 0x43 (Table 7-11). The back channel frequency can be controlled several ways:

  1. Register 0x23[6] sets the divider that controls the back channel frequency based on the internal oscillator. 0x23[6] = 0 sets the divider to 4 and 0x23[6] = 1 sets the divider to 2. As long as BC_HS_CTL (0x23[4]) is set to 0, the back channel frequency is either 5 Mbps or 10 Mbps, based on this bit.
  2. Register 0x23[4] enables the high-speed back channel. This can also be pin-strapped through MODE_SEL1 (see Table 7-3). This bit overrides 0x23[6] and sets the divider for the back channel frequency to 1. Setting this bit to 1 sets the back channel frequency to 20 Mbps.
The back channel frequency has variation of ±20%. Note: The back channel frequency must be set to 5 Mbps when paired with a DS90UB925Q-Q1, DS90UB921-Q1, DS90UB929-Q1, or DS90UB927Q-Q1. See Table 7-3 for details about configuring the D_GPIOs in various modes.

The HSCC modes replace normal back-channel signaling with dedicated GPIOs or SPI data, allowing greater bandwidth for those functions. The HSCC Modes are enabled by setting the HSCC_MODE field in the HSCC_CONTROL register 0x43[2:0] in the DS90UB948-Q1. The HSCC modes eliminate the normal signaling such as Device ID, Capabilities, and RX Lock detect. It is intended to be turned on after obtaining RX Lock in normal back channel mode. Hence, the serializer properly determines capabilities prior to HSCC mode initiation. HSCC mode prevents loading capabilities, and it should only be enabled after RX Lock is established.

Table 7-3 Back Channel D_GPIO Effective Frequency
HSCC_MODE (0x43[2:0])MODENUMBER OF D_GPIOsSAMPLES PER FRAMED_GPIO EFFECTIVE FREQUENCY(1) (kHz)D_GPIOs ALLOWED
5 Mbps BC(2)10 Mbps BC(3)20 Mbps BC(4)
000Normal413366133D_GPIO[3:0]
011Fast46200400800D_GPIO[3:0]
010Fast2103336661333D_GPIO[1:0]
001Fast11550010002000D_GPIO0
(1) The effective frequency assumes the worst-case back channel frequency (–20%) and a 4×sampling rate.
(2) 5 Mbps corresponds to BC FREQ SELECT = 0 & BC_HS_CTL = 0.
(3) 10 Mbps corresponds to BC FREQ SELECT = 1 & BC_HS_CTL = 0.
(4) 20 Mbps corresponds to BC FREQ SELECT = X & BC_HS_CTL = 1.