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

5.2.4 Byte or Transaction Timeout

The UCD9081 enforces a maximum byte or transaction timeout period of approximately 5 ms on the I2C master. This time is measured from the previous bytes falling SDA (during START, or repeated START) to the current bytes falling SDA (during START, or repeated START). See Figure 5-7. This timeout is not enforced for the cases when the UCD9081 holds SCL low (see Section 5.2.2) to insert additional wait states (that is, the byte timer is reset and does not expire during the stretch period).

GUID-ABDCC5BB-BECB-4E51-95FC-DBBA71B346B2-low.gifFigure 5-7 Byte Timeout Requirements

Additionally, the byte timeout period is reset when a new bit (rising edge of SCL) arrives. So, excluding the four exceptions described in Section 5.2.3, the byte timeout period applies.