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

4.3 Packet Error Checking (PEC) Implementation

By default, the USB Interface Adapter firmware implements PEC for all the different commands. However, the implementation of PEC byte is optional. There is a special host PC to USB Interface Adapter command that can be used to turn PEC on or off.

If PEC is on or enabled, the firmware in the USB Interface Adapter either appends a PEC byte to a command sent to one or multiple targeted devices or checks the validity of a PEC byte received from a target device.