SCPS279 February   2022 TCA9537

PRODUCTION DATA  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
  4. 4 Revision History
  5. 5 Pin Configuration and 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 Timing Requirements
    7. 6.7 I2C Bus Timing Requirements
    8. 6.8 Switching Characteristics
    9. 6.9 Typical Characteristics
  7. 7 Parameter Measurement Information
  8. 8 Detailed Description
    1. 8.1 Overview
    2. 8.2 Functional Block Diagram
    3. 8.3 Feature Description
      1. 8.3.1 I/O Port
      2. 8.3.2 Interrupt (INT) Output
      3. 8.3.3 RESET Input
    4. 8.4 Device Functional Modes
      1. 8.4.1 Power-On Reset
      2. 8.4.2 Powered-Up
    5. 8.5 Programming
      1. 8.5.1 I2C Interface
        1. 8.5.1.1 Writes
        2. 8.5.1.2 Reads
      2. 8.5.2 Software Reset Call
    6. 8.6 Register Maps
      1. 8.6.1 Device Address
      2. 8.6.2 Control Register and Command Byte
      3. 8.6.3 Register Descriptions
  9. 9 Application Information Disclaimer
    1. 9.1 Application Information
    2. 9.2 Typical Application
      1. 9.2.1 Design Requirements
        1. 9.2.1.1 Minimizing ICC When I/Os Control LEDs
      2. 9.2.2 Detailed Design Procedure
      3. 9.2.3 Application Curves
  10. 10Power Supply Recommendations
    1. 10.1 Power-On Reset
  11. 11Layout
    1. 11.1 Layout Guidelines
    2. 11.2 Layout Example
  12. 12Device and Documentation Support
    1. 12.1 Documentation Support
      1. 12.1.1 Related Documentation
    2. 12.2 Receiving Notification of Documentation Updates
    3. 12.3 Support Resources
    4. 12.4 Trademarks
    5. 12.5 Electrostatic Discharge Caution
    6. 12.6 Glossary
  13. 13Mechanical, Packaging, and Orderable Information

8.5.2 Software Reset Call

The Software Reset call is a command send from the controller on the I2C bus that instructs all devices that support the command to be reset to power-up values. In order for it to function as expected, the I2C bus must be functional and no devices can be hanging the bus.

The Software Reset Call is defined as the following steps:

  1. A START condition is sent by the I2C bus controller.
  2. The address used is the reserved General Call I2C bus address '0000 000' with the R/W bit set to 0. The byte sent is 0x00.
  3. Any devices supporting the General Call functionality will ACK. If the R/W bit is set to 1 (read), the device will NACK.
  4. Once the General Call address is acknowledged, the controller sends only 1 byte of data equal to 0x06. If the data byte is any other value, the device will NOT acknowledge or reset. If more than 1 byte is sent, no more bytes will be acknowledged, and the device will ignore this I2C message, considering it invalid.
  5. After the 1 byte of data (0x06) is sent, the controller sends a STOP condition to end the Software Reset sequence. A repeated START condition will be ignored by the device, and no reset is performed.

Once the above steps are completed successfully, the device performs a reset. This clears all register values back to power-on defaults. All P-ports are configured as inputs.