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
5.4.6.4.2 Internally Generated FrameSync

In internal FrameSync mode, an internally generated FrameSync signal is sent to one or more of the attached FPD3 serializers via a GPIO signal in the back channel.

FrameSync operation is controlled by the FS_CTL 0x18, FS_HIGH_TIME_x, and FS_LOW_TIME_x 0x19–0x1A registers. The resolution of the FrameSync generator clock (FS_CLK_PD) is derived from the back channel frame period (BC_FREQ_SELECT register). For 2.5-Mbps back-channel operation, the frame period is 12 µs (30 bits × 400 ns/bit).

Once enabled, the FrameSync signal is sent continuously based on the programmed conditions.

Enabling the internal FrameSync mode is done by setting the FS_GEN_ENABLE control in the FS_CTL (0x18) register to a value of 1. The FS_MODE field controls the clock source used for the FrameSync generation. The FS_GEN_MODE field configures whether the duty cycle of the FrameSync is 50/50 or whether the high and low periods are controlled separately. The FrameSync high and low periods are controlled by the FS_HIGH_TIME and FS_LOW_TIME registers.

The accuracy of the internally generated FrameSync is directly dependent on the accuracy of the internal oscillator used to generate the back-channel reference clock. The internal oscillator has ±5% variation over process, voltage, and temperature.

GUID-ECD08367-6A1F-42CD-BCFB-DCFE1A648F0F-low.gifFigure 5-5 Internal FrameSync Signal

The following example shows generation of a FrameSync signal at 60 pulses per second. Mode settings:

  • Programmable high/low periods: FS_GEN_MODE 0x18[1]=0
  • Use port 0 back channel frame period: FS_MODE 0x18[7:4]=0x0
  • Back channel rate of 2.5 Mbps: BC_FREQ_SELECT for port 0 0x58[2:0]=0x0
  • Initial FS state of 0: FS_INIT_STATE 0x18[2]=0

Based on mode settings, the FrameSync is generated based upon FS_CLK_PD of 12 μs.

The total period of the FrameSync is (1 sec / 60 Hz) / 12 µs or approximately 1,389 counts.

For a 10% duty cycle, set the high time to 139 (0x008A) cycles, and the low time to 1,250 (0x04E1) cycles:

  • FS_HIGH_TIME_1: 0x19 = 0x00
  • FS_HIGH_TIME_0: 0x1A = 0x8A
  • FS_LOW_TIME_1: 0x1B = 0x04
  • FS_LOW_TIME_0: 0x1C = 0xE1