SNLS507C September   2016  – December 2022 DS90UB934-Q1

PRODUCTION DATA  

  1.   Features
  2. 1Applications
  3. 2Description
  4. 3Revision History
  5.   Pin Configuration and Functions
  6. 4Specifications
    1. 4.1 Absolute Maximum Ratings
    2. 4.2 ESD Ratings
    3. 4.3 Recommended Operating Conditions
    4. 4.4 Thermal Information
    5. 4.5 DC Electrical Characteristics
    6. 4.6 AC Electrical Characteristics
    7. 4.7 Recommended Timing for the Serial Control Bus
    8. 4.8 Typical Characteristics
  7. 5Detailed Description
    1. 5.1 Overview
      1. 5.1.1 Functional Description
    2. 5.2 Functional Block Diagram
    3. 5.3 Feature Description
      1. 5.3.1 Serial Frame Format
      2. 5.3.2 Line Rate Calculations for the DS90UB933/934
      3. 5.3.3 Deserializer Multiplexer Input
    4. 5.4 Device Functional Modes
      1. 5.4.1 RX MODE Pin
      2. 5.4.2 DVP Output Control
        1. 5.4.2.1 LOCK Status
      3. 5.4.3 Input Jitter Tolerance
      4. 5.4.4 Adaptive Equalizer
      5. 5.4.5 Channel Monitor Loop-Through Output Driver
        1. 5.4.5.1 Code Example for CMLOUT FPD3 RX Port 0:
      6. 5.4.6 GPIO Support
        1. 5.4.6.1 Back Channel GPIO
        2. 5.4.6.2 GPIO Pin Status
        3. 5.4.6.3 Other GPIO Pin Controls
        4. 5.4.6.4 FrameSync Operation
          1. 5.4.6.4.1 External FrameSync Control
          2. 5.4.6.4.2 Internally Generated FrameSync
            1. 5.4.6.4.2.1 Code Example for Internally Generated FrameSync
    5. 5.5 Programming
      1. 5.5.1 Serial Control Bus
        1. 5.5.1.1 I2C Target Operation
        2. 5.5.1.2 Remote Target Operation
        3. 5.5.1.3 Remote I2C Targets Data Throughput
        4. 5.5.1.4 Remote Target Addressing
        5. 5.5.1.5 Broadcast Write to Remote Target Devices
        6. 5.5.1.6 Code Example for Broadcast Write
      2. 5.5.2 Interrupt Support
        1. 5.5.2.1 Code Example to Enable Interrupts
        2. 5.5.2.2 FPD-Link III Receive Port Interrupts
        3. 5.5.2.3 Code Example to Readback Interrupts
        4. 5.5.2.4 Built-In Self Test (BIST)
          1. 5.5.2.4.1 BIST Configuration and Status
    6. 5.6 Register Maps
      1. 5.6.1 Register Description
      2. 5.6.2 Registers
      3. 5.6.3 Indirect Access Registers
      4. 5.6.4 Indirect Access Register Map
        1. 5.6.4.1 FPD3 Channel 0 Registers
        2. 5.6.4.2 FPD3 Channel 1 Registers
        3. 5.6.4.3 FPD3 RX Shared Registers
  8. 6Application and Implementation
    1. 6.1 Application Information
    2. 6.2 Power Over Coax
    3. 6.3 Typical Application
      1. 6.3.1 Design Requirements
      2. 6.3.2 Detailed Design Procedure
      3. 6.3.3 Application Curves
    4. 6.4 System Examples
    5. 6.5 Power Supply Recommendations
      1. 6.5.1 VDD Power Supply
      2. 6.5.2 Power-Up Sequencing
      3. 6.5.3 PDB Pin
      4. 6.5.4 Ground
    6. 6.6 Layout
      1. 6.6.1 Layout Guidelines
        1. 6.6.1.1 DVP Interface Guidelines
      2. 6.6.2 Layout Example
  9.   Mechanical, Packaging, and Orderable Information
  10. 7Device and Documentation Support
    1. 7.1 Documentation Support
      1. 7.1.1 Related Documentation
    2. 7.2 Glossary
    3. 7.3 Receiving Notification of Documentation Updates
    4. 7.4 Support Resources
    5. 7.5 Trademarks
  11.   Mechanical, Packaging, and Orderable Information

5.5.1.3 Remote I2C Targets Data Throughput

Since the BCC buffers each I2C data byte and regenerates the I2C protocol on the remote side of the link, the overall I2C throughput will be reduced. The reduction is dependent on the operating frequencies of the local and remote interfaces. The local I2C rate is based on the host controller clock rate, while the remote rate depends on the settings for the proxy I2C controller (SCL frequency).

For purposes of understanding the effects of the BCC on data throughput from a host controller to a remote I2C controller, the approximate bit rate including latency timings across the control channel can be calculated by the following:

9 bits / ((Host_bit * 9) + (Remote_bit * 9) + FCdelay + BCCdelay)

Example of DS90UB934/933 chipset:

For the 100 kbit/s (100 kHz) :

Host_bit = 10us (100 kHz)

Remote_bit = 13us (77 kHz)

FCdelay = 1us (max)

BCCdelay = 12us (typical value for 2.5 Mbps back channel rate)

Effective rate = 9bits / (90us + 117us + 1us + 12us) = 41 kbit/s

Table 5-8 Typical Achievable Bit Rates
Host I2C rate Remote I2C rate Net bit rate
100 kbit/s 77 kbit/s (default settings) 41 kbit/s
400 kbit/s 100 kbit/s 71.7 kbit/s
1 Mbit/s 100 kbit/s 80.3 kbit/s
1 Mbit/s 400 kbit/s 202.2 kbit/s
1 Mbit/s 1 Mbit/s 290.3 kbit/s

Since the I2C protocol includes overhead for sending address information as well as START and STOP bits, the actual data throughput depends on the size and type of transactions used. Use of large bursts to read and write data will result in higher data transfer rates.