SPRACO5 September   2019 TMS320F280021 , TMS320F280021-Q1 , TMS320F280023 , TMS320F280023-Q1 , TMS320F280023C , TMS320F280025 , TMS320F280025-Q1 , TMS320F280025C , TMS320F280025C-Q1 , TMS320F280040-Q1 , TMS320F280040C-Q1 , TMS320F280041 , TMS320F280041-Q1 , TMS320F280041C , TMS320F280041C-Q1 , TMS320F280045 , TMS320F280048-Q1 , TMS320F280048C-Q1 , TMS320F280049 , TMS320F280049-Q1 , TMS320F280049C , TMS320F280049C-Q1 , TMS320F28384D , TMS320F28384D-Q1 , TMS320F28384S , TMS320F28384S-Q1 , TMS320F28386D , TMS320F28386D-Q1 , TMS320F28386S , TMS320F28386S-Q1 , TMS320F28388D , TMS320F28388S , TMS320F28P650DH , TMS320F28P650DK , TMS320F28P650SH , TMS320F28P650SK , TMS320F28P659DK-Q1

 

  1.   Leveraging High Resolution Capture (HRCAP) for Single Wire Data Transfer
    1.     Trademarks
    2. 1 Introduction
    3. 2 System Showcase
      1. 2.1 HRPWM: Encoding Unit
      2. 2.2 HRCAP: Decoding Unit
    4. 3 Software Flow
      1. 3.1 User Configurable Parameters
      2. 3.2 SFO Background Loop
      3. 3.3 Interrupt Based Encoding and Decoding
      4. 3.4 Offset Calibration
    5. 4 Experimental Setup and Results
    6. 5 Summary
    7. 6 References

Summary

The proposed data transfer technique leverages the High Resolution Capture (HRCAP) module of C2000 for communicating reasonably high resolution data with low latency just using a single wire. Compared with the normal resolution capture unit (eCAP), HRCAP allows the system to operate at significantly high transmission frequencies, which is reflected in the transmission latencies shown in Table 1. Also looking at Table 1, clearly there is a trade-off between ENOB and transmission latency because at very high transmission frequencies, the transmission latency is less but the ENOB achieved is low. While at lower transmission frequencies, ENOB achieved is relatively high but the transmission latency is large. The transmission latency is less but the ENOB achieved is also low, while at lower transmission frequencies, ENOB achieved is relatively high but the transmission latency is large. Thus, based on the application, you need to choose the appropriate transmission frequency. With all of the other communication peripherals already existing in the C2000 devices, the proposed single wire technique offers an additional data transfer mechanism, which would be very handy for communication across isolation offering a significant cost advantage. Comparing this technique with the similar clock frequency (hundreds of KHz) communication mechanisms like inter-integrated circuit (I2C) and universal asynchronous receiver/transmitter (UART), the transmission latency is quite low as it encodes the entire data packet (10 to 12 bits) in a single pulse, unlike those standard serial protocols where unit pulse is used for encoding only a single bit. The demo examples showcasing this technique are available in C2000Ware software and support user-configurable parameters that will allow customers to quickly evaluate the example for any desired configuration.