SNLS398H January   2012  – February 2018 DS125DF410

PRODUCTION DATA.  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
    1.     Typical Application Diagram
  4. 4 Revision History
  5. 5 Pin Configuration and Functions
    1.     Pin 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 Electrical Characteristics
    6. 6.6 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 Device Data Path Operation
      2. 7.3.2 Signal Detect
      3. 7.3.3 CTLE
      4. 7.3.4 DFE
      5. 7.3.5 Clock and Data Recovery
      6. 7.3.6 Output Driver
      7. 7.3.7 Device Configuration
        1. 7.3.7.1 Rate and Subrate Setting
    4. 7.4 Device Functional Modes
      1. 7.4.1 SMBus Master Mode and SMBus Slave Mode
      2. 7.4.2 Address Lines <ADDR_[3:0]>
      3. 7.4.3 SDA and SDC
      4. 7.4.4 Standards-Based Modes
        1. 7.4.4.1 Ref_mode 3 Mode (Reference Clock Required)
        2. 7.4.4.2 False Lock Detector Setting
        3. 7.4.4.3 Reference Clock In
        4. 7.4.4.4 Reference Clock Out
        5. 7.4.4.5 Driver Output Voltage
        6. 7.4.4.6 Driver Output De-Emphasis
        7. 7.4.4.7 Driver Output Rise/Fall Time
        8. 7.4.4.8 INT
        9. 7.4.4.9 LOCK_3, LOCK_2, LOCK_1, and LOCK_0
    5. 7.5 Programming
      1. 7.5.1  SMBus Strap Observation
      2. 7.5.2  Device Revision and Device ID
      3. 7.5.3  Control/Shared Register Reset
      4. 7.5.4  Interrupt Channel Flag Bits
      5. 7.5.5  SMBus Master Mode Control Bits
      6. 7.5.6  Resetting Individual Channels of the Retimer
      7. 7.5.7  Interrupt Status
      8. 7.5.8  Overriding the CTLE Boost Setting
      9. 7.5.9  Overriding the VCO Search Values
      10. 7.5.10 Overriding the Output Multiplexer
      11. 7.5.11 Overriding the VCO Divider Selection
      12. 7.5.12 Using the PRBS Generator
      13. 7.5.13 Using the Internal Eye Opening Monitor
      14. 7.5.14 Overriding the DFE Tap Weights and Polarities
      15. 7.5.15 Enabling Slow Rise/Fall Time on the Output Driver
      16. 7.5.16 Inverting the Output Polarity
      17. 7.5.17 Overriding the Figure of Merit for Adaptation
      18. 7.5.18 Setting the Rate and Subrate for Lock Acquisition
      19. 7.5.19 Setting the Adaptation/Lock Mode
      20. 7.5.20 Initiating Adaptation
      21. 7.5.21 Setting the Reference Enable Mode
      22. 7.5.22 Overriding the CTLE Settings Used for CTLE Adaptation
      23. 7.5.23 Setting the Output Differential Voltage
      24. 7.5.24 Setting the Output De-Emphasis Setting
    6. 7.6 Register Maps
      1. 7.6.1 Register Information
      2. 7.6.2 Bit Fields in the Register Set
      3. 7.6.3 Writing to and Reading from the Control/Shared Registers
      4. 7.6.4 Channel Select Register
      5. 7.6.5 Reading to and Writing from the Channel Registers
  8. 8 Application and Implementation
    1. 8.1 Application Information
    2. 8.2 Typical Application
      1. 8.2.1 Design Requirements
      2. 8.2.2 Detailed Design Procedure
      3. 8.2.3 Application Curves
  9. 9 Power Supply Recommendations
  10. 10Layout
    1. 10.1 Layout Guidelines
    2. 10.2 Layout Example
  11. 11Device and Documentation Support
    1. 11.1 Documentation Support
      1. 11.1.1 Related Documentation
    2. 11.2 Trademarks
    3. 11.3 Electrostatic Discharge Caution
    4. 11.4 Glossary
  12. 12Mechanical, Packaging, and Orderable Information

7.4.2 Address Lines <ADDR_[3:0]>

In either SMBus master or SMBus slave mode the DS125DF410 must be assigned an SMBus address. A unique address should be assigned to each device on the SMBus.

The SMBus address is latched into the DS125DF410 on power-up. The address is read in from the state of the <AD3:AD0> lines (pins 16, 21, 40, and 45 respectively) upon power-up. In either SMBus mode these address lines are input pins on power-up.

The DS125DF410 can be configured with any of 16 SMBus addresses. The SMBus addressing scheme uses the least-significant bit of the SMBus address as the Read/Write_N address bit. When an SMBus device is addressed for writing, this bit is set to 0; for reading, to 1. Table 1 below shows the write address setting for the DS125DF410 versus the values latched in on the address lines at power-up.

The address byte sent by the SMBus master over the SMBus is always 8 bits long. The least-significant bit indicates whether the address is for a write operation, in which the master will output data to the SMBus to be read by the slave, or a read operation, in which the slave will output data to the SMBus to be read by the master. if the least-significant bit is a 0, the address is for a write operation. If it is a 1, the address is for a read operation. Accordingly, SMBus addresses are sometimes referred to as seven-bit addresses. To produce the write address for the SMBus, the seven-bit address is left-shifted by one bit. To produce the read address, it is left shifted by one bit and the least-significant bit is set to 1. Table 1 shows the seven-bit addresses corresponding to each set of address line values.

When the DS125DF410 is used in SMBus slave mode, the READ_EN pin must be tied low. If it is tied high or floating, the DS125DF410 will not latch in its address from the address lines on power-up. When the READ_EN pin is tied high in SMBus slave mode i.e. when the EN_SMB pin (pin 20) is tied high, the DS125DF410 will revert to an SMBus write address of 0x30. This is a test feature. If there are multiple DS125DF410s on the same SMBus, they will all revert to an SMBus write address of 0x30, which can cause SMBus collisions and failure to access the DS125DF410s over the SMBus.

Table 1. DS125DF410 SMBus Write Address Assignment

ADDR_3ADDR_2ADDR_1ADDR_0SMBus
WRITE
ADDRESS		SEVEN-BIT
SMBus
ADDRESS
0 0 0 0 0x30 0x18
0 0 0 1 0x32 0x19
0 0 1 0 0x34 0x1a
0 0 1 1 0x36 0x1b
0 1 0 0 0x38 0x1c
0 1 0 1 0x3a 0x1d
0 1 1 0 0x3c 0x1e
0 1 1 1 0x3e 0x1f
1 0 0 0 0x40 0x20
1 0 0 1 0x42 0x21
1 0 1 0 0x44 0x22
1 0 1 1 0x46 0x23
1 1 0 0 0x48 0x24
1 1 0 1 0x4a 0x25
1 1 1 0 0x4c 0x26
1 1 1 1 0x4e 0x27

Once the DS125DF410 has latched in its SMBus address, its registers can be read and written using the two pins of the SMBus interface, Serial Data (SDA) and Serial Data Clock (SDC).