SNAU305 February   2025 LMH1229 , LMH1239

 

  1.   1
  2.   LMH1229 and LMH1239 Programming Guide
  3.   Trademarks
  4. 1Access Methods
    1. 1.1 Register Programming Through SMBus
    2. 1.2 Register Programming Through SPI
    3. 1.3 Register Pages
  5. 2Register Command Syntax
  6. 3Device Configurations
    1. 3.1  Common Device Configuration
    2. 3.2  Common Register Commands
      1. 3.2.1 Channel Control
      2. 3.2.2 LMH12x9 Resets
        1. 3.2.2.1 LMH12x9 ENABLE Pin Override
        2. 3.2.2.2 LMH12x9 Share, CDR, and EQ/Drivers Page Resets
    3. 3.3  IN_MUX_SEL Override
    4. 3.4  Signal Detect Status for SDI_IN± and SDI_IN1±
      1. 3.4.1 Force Signal Detect Power Down
    5. 3.5  Lock Data Rate Indication
    6. 3.6  CDR Loop Bandwidth Override
    7. 3.7  Selective SMPTE Data Rate Lock
      1. 3.7.1 Digital Mute Reference Threshold
      2. 3.7.2 CTLE Index Check and Manual CTLE Override
    8. 3.8  Eye Opening Monitoring Operation
      1. 3.8.1 Fast EOM
        1. 3.8.1.1 Fast EOM Operation
      2. 3.8.2 Read Horizontal and Vertical Eye Opening
    9. 3.9  SDI_OUT±, OUT0± and OUT1± Default Mode of Operation
      1. 3.9.1 SDI_OUT±, OUT0± and OUT1± Independent Control
    10. 3.10 Invert OUT0±, OUT1±, and SDI_OUT± Data Polarity
    11. 3.11 OUT0±, OUT1±, and SDI_OUT± Driver Settings
      1. 3.11.1 OUT0± and OUT1± VOD Settings
      2. 3.11.2 OUT0± and OUT1± De-Emphasis Settings
      3. 3.11.3 SDI_OUT± VOD Settings
      4. 3.11.4 SDI_OUT± Pre-Emphasis
      5. 3.11.5 Output Driver Power Down
      6. 3.11.6 Cable Fault Detection (CFD)
    12. 3.12 LOCK_N Pin Output Settings
      1. 3.12.1 Interrupt Outputs Programmed by Interrupt Registers
    13. 3.13 PRBS Generator and Checker
    14. 3.14 CDR Lock Timing Control
      1. 3.14.1 Watchdog Timer
  7. 4Register Maps
    1. 4.1 Share Registers
    2. 4.2 CDR Registers
    3. 4.3 EQ_Drivers Registers

3.11.2 OUT0± and OUT1± De-Emphasis Settings

The LMH12x9 features the ability to provide Tx equalization de-emphasis for OUT0± and OUT1±. By default, de-emphasis values for OUT0± and OUT1± are applied depending on the VOD_DE pin setting.

The default de-emphasis settings can be overridden by register control.

Table 3-39 OUT0± and OUT1± De-Emphasis Settings
COMMANDREGISTERVALUEMASK//COMMENTS
RAWFF0507//Select EQ/Drivers Register Page
RAW341010//Override de-emphasis control from VOD_DEM_SEL pin for OUT0±
RAW340007//OUT0 de-emphasis setting set to 0.0dB
RAW340207//OUT0 de-emphasis setting set to –1.0dB
RAW340404//OUT0 de-emphasis setting set to –2.4dB

RAW

34

06

06

//OUT0 de-emphasis setting set to –6.1dB

RAW

36

10

10

//Override de-emphasis control from VOD_DEM_SEL pin for OUT1±

RAW

36

00

07

//OUT1± de-emphasis setting set to 0.0dB

RAW

36

02

07

//OUT1± de-emphasis setting set to –1.0dB

RAW

36

04

04

//OUT1± de-emphasis setting set to –2.4dB

RAW

36

06

06

//OUT1± de-emphasis setting set to –6.1dB