SLVA275C january   2010  – may 2023 UCD9081

 

  1.   Abstract
  2.   Trademarks
  3. 1Introduction
  4. 2Hardware
    1. 2.1 Package: RHB (S-PQFP-N32), 32-Pin Plastic Quad Flatpack
    2. 2.2 Hardware and Pinout
    3. 2.3 Detailed Pin Descriptions
      1. 2.3.1 RST
      2. 2.3.2 SDA
      3. 2.3.3 SCL
      4. 2.3.4 ADDRx
      5. 2.3.5 ROSC
  5. 3Software
    1. 3.1 Data File Format
    2. 3.2 I2C Transactions
    3. 3.3 Device Version
    4. 3.4 Checksum
    5. 3.5 Sample Configuration Data File
      1. 3.5.1 Factory Default
      2. 3.5.2 EVM Default Configuration
    6. 3.6 I2C Write and Read Transaction Formats
      1. 3.6.1 I2C Write Transaction
      2. 3.6.2 I2C Read Transaction
    7. 3.7 Pseudo I2C Write and Read Transactions
      1. 3.7.1 UCD9081 I2C Transactions for Writing User Data and PARAMS
      2. 3.7.2 UCD9081 I2C Transactions for Reading User Data and PARAMS
  6. 4User Configuration
    1. 4.1 Configuration Parameter Memory Map
    2. 4.2 Configuration Parameter Detail
      1. 4.2.1  GpDir
      2. 4.2.2  NegateEnablePolarity
      3. 4.2.3  SeqEventPending
      4. 4.2.4  SequenceEventParameters
      5. 4.2.5  SequenceEventLink
      6. 4.2.6  SequenceEventData
      7. 4.2.7  DependencyMasks
      8. 4.2.8  UnderVoltageThresholds
      9. 4.2.9  OverVoltageThresholds
      10. 4.2.10 RampTime
      11. 4.2.11 OutOfRegulationWidth
      12. 4.2.12 UnsequenceTime
      13. 4.2.13 EnablePolarity
      14. 4.2.14 SaveRailLog
      15. 4.2.15 ReferenceSelect
      16. 4.2.16 LastUnusedSeq
      17. 4.2.17 IgnoreGlitchAlarms
      18. 4.2.18 IgnoreFlashErrorLog
      19. 4.2.19 Checksum
  7. 5Additional Considerations
    1. 5.1 Embedded Application
    2. 5.2 Timing
      1. 5.2.1 UCD9081 Startup
      2. 5.2.2 Clock Stretching After Flash Erase
      3. 5.2.3 Bit Timeout
      4. 5.2.4 Byte or Transaction Timeout
  8. 6References
  9. 7Revision History

4.2.15 ReferenceSelect

The ReferenceSelect field in the configuration parameters specifies which voltage reference is used on the UCD9080. The selected reference can be internal (2.5-V), or external via VCC (3.3 V). The register address is 0xE186 and contents are as follows:

GUID-7241B2CB-CEC5-4721-BB06-FFDEA595DECA-low.gif

The default value for this register is 0x08F2, which selects the external reference.