TIDUE74F April   2018  – March 2026

 

  1.   1
  2.   Description
  3.   Resources
  4.   Features
  5.   Applications
  6.   6
  7. 1System Description
    1. 1.1 Key System Specifications
  8. 2System Overview
    1. 2.1 Block Diagram
    2. 2.2 Highlighted Products
      1. 2.2.1 C2000™ Real-Time MCU LaunchPad™ Development Kit
      2. 2.2.2 SN65HVD78
      3. 2.2.3 TLV702
      4. 2.2.4 TPS22918-Q1
    3. 2.3 Design Considerations
      1. 2.3.1 Tamagawa T-Format Protocol
      2. 2.3.2 C2000 T-Format Encoder Interface Overview
      3. 2.3.3 TIDM-1011 Board Implementation
      4. 2.3.4 MCU Resource Requirements
      5. 2.3.5 Device-Specific Resource Usage
        1. 2.3.5.1 CRC Calculations
        2. 2.3.5.2 Input, Output Signals, and CLB Tiles
      6. 2.3.6 CLB T-Format Implementation Details
        1. 2.3.6.1 Transaction Waveforms
          1. 2.3.6.1.1 IDLE State
          2. 2.3.6.1.2 TRANSMIT_DATA State
          3. 2.3.6.1.3 WAIT_FOR_START State
          4. 2.3.6.1.4 RECEIVE_DATA State
        2. 2.3.6.2 Communication Tile Design
        3. 2.3.6.3 Logic View
      7. 2.3.7 CLB Receive Data CRC Implementation
      8. 2.3.8 PM T-Format Encoder Interface Library
        1. 2.3.8.1 PM T-Format Reference Implementation Commands
        2. 2.3.8.2 Functions Supported in PM T-Format Reference Implementation
  9. 3Hardware, Software, Testing Requirements, and Test Results
    1. 3.1 Hardware
      1. 3.1.1 TIDM-1011 Jumper Configuration
    2. 3.2 Software
      1. 3.2.1 C2000 Driver Library (DriverLib)
      2. 3.2.2 C2000 SysConfig
      3. 3.2.3 C2000 Configurable Logic Block Tool
      4. 3.2.4 Installing Code Composer Studio™ and C2000WARE-MOTORCONTROL-SDK
      5. 3.2.5 Locating the Reference Software
    3. 3.3 Testing and Results
      1. 3.3.1 Hardware Configuration
      2. 3.3.2 Building and Loading Project
      3. 3.3.3 Running Code
      4. 3.3.4 Cable Length Validation
      5. 3.3.5 Benchmarks
      6. 3.3.6 Troubleshooting
  10. 4Design Files
  11. 5Related Documentation
    1. 5.1 Trademarks
  12. 6Terminology
  13. 7About the Authors
  14. 8Revision History

3.3.6 Troubleshooting

Examining the following waveforms can assist in troubleshooting. Refer to the I/O diagrams in the design description:

  • The CLB generated SPI clock.
  • The output data from the SPI. This is the request to the encoder.
  • The input data to the SPI. This is the response.
  • The TxEN signal. This signal must be high during the request transmission.
  • The encoder data signal (D+/D-) between the RS485 line driver and the encoder. Note: The data is a differential signal. Therefore, observation requires a special probe.
  1. If the request is not transmitted by the SPI:
    • Check the connection between the SPICLK and the CLB. The CLB drives the SPI CLK. This connection can be internal to the MCU on all devices except F2837xD. On F2837xD this connection must be made externally.
    • Observe the SPI registers after the command setup and again after start operation. If the SPI receives the clock, the TX FIFO level decreases while the RX FIFO level increases.
  2. The encoder does not respond:
    • Confirm TxEN is high during the request transmission.
    • Check the SPI clock frequency. The clock frequency must be 2.5 MHz for the encoder to respond. If the clock is not 2.5 MHz, then check the frequency configuration (TFORMAT_FREQ_DIVIDER) in the system example header file.
    • Check that the encoder is properly powered. In some cases the LaunchPad is not able to supply the current required by the encoder. Try providing power to the encoder separately, making sure all grounds are tied together.
  3. The SPI CLK is observed during transmit but not during the response time:
    • Check the encoder's connection to the test hardware.
    • If you have modified the design:
      • Check that the response pin is routed into the correct CLB tile and to the correct input of that tile. The CLB must detect the encoder's response. Only then does the CLB generate the CLB_SPI_CLK.
      • If the CLB is driving SPI CLK internally, check that the tile and tile output enable are correct. Only certain tiles can access a specific SPI module. This can change on different devices.