SLLU349 August   2022

 

  1.   Abstract
  2.   Trademarks
  3. 1Read This First
    1. 1.1 Information About Cautions and Warnings
    2. 1.2 FCC Warning
  4. 2What is in the Box
    1. 2.1 List of Hardware Items for Operation
    2. 2.2 List of Software Items for Operation
  5. 3Summary of Hardware Design
    1. 3.1 Ribbon-Cable Connector J2 and Pinout
    2. 3.2 Configuration of Pullup Resistors for Pins 8, 9, and 10
    3. 3.3 LED Indication of USB Attached
    4. 3.4 Step-by-Step Instructions for Operation and Troubleshooting
  6. 4PMBUS and SMBUS Communications
    1. 4.1 Basic SMBUS Transaction Types Supported
    2. 4.2 Special Signals Used for PMBUS and SMBUS Communications
    3. 4.3 Packet Error Checking (PEC) Implementation
    4. 4.4 Communication Clock Speed and Clock Stretching

4.4 Communication Clock Speed and Clock Stretching

The default clock speed is 100 kHz, which is compatible with PMBUS 1.0 and SMBUS 2.0. For compatibility with future PMBUS specs, the clock speed can be increased to 400 kHz or 1 MHz.

As per the SMBus protocol, the minimum and maximum value for the Clock Stretching is 25 ms and 35 ms, respectively.