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

3.3.5 Benchmarks

Table 3-6 lists the C28x CPU cycles required to execute T-Format library functions from RAM. This data was collected using:

  • C2000 Codegen Tools V22.6.0.LTS
  • float_support: fpu32
  • tmu_support: tmu0
  • fp_mode: relaxed
  • abi: eabi

Table 3-6 Cycle-Count Benchmarks
Cycles: -O2 -mf2
Function CRC Calculation(1) TX CRC by VCRC(2)
RX CRC by CLB(3)		 TX and RX CRC by
C28x Lookup Table(4)
setupCommandReadEEPROM Transmit 266 264
setupCommandWriteEEPROM Transmit 280 291
setupCommandReadoutOrReset N/A 231 222
spiRxISR N/A 418 418
startOperation N/A 19 14
receiveDataID0_1_7_8_C Receive 41 118
receiveDataID2 Receive 35 81
receiveDataID3 Receive 64 218
receiveDataID6 Receive 57 101
receiveDataIDC Receive 53 97
updateEncoderID N/A 1 1
updatePositionsOrTurns N/A 18 18
(1) The indicated functions calculate either a transmit-data CRC or a received-data CRC. N/A indicates the function does not require a CRC calculation.
(2) The VCRC extension to the C28x CPU calculates the transmit-data CRC.
(3) The CLB calculates the received-data CRC as the response is incoming. This method uses an additional CLB tile and requires CLB Type 2 or later.
(4) Both transmit and receive CRCs are calculated by the C28x using a look-up table.

Table 3-7 lists the code-size, in 16-bit words, corresponding to each of the library source files. The C28x lookup-table takes 256 words of RAM or Flash that is not reflected in this table.

Table 3-7 Code-size in 16-bit Words
Code-Size: -O2 -mf2
Source File TX CRC: VCRC
RX CRC: CLB		 TX and RX CRC:
C28x Lookup Table
pm_tformat_source 936 923
clb_config 480 246
pm_tformat_crc 26 148
pm_tformat_crc_vcrc 14 N/A