• State Resolved
  • Locked Locked
  • Replies 2 replies
  • Subscribers 82 subscribers
  • Views 455 views
  • Users 0 members are here
Support feedback
Options
Options
Similar topics

This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

TMS320F28027F: Interfacing with DRV8301. SPI/SCI vs Trip zone inputs

Simo Sihvonen
Intellectual 300 points
Part Number: TMS320F28027F
Other Parts Discussed in Thread: DRV8301-69M-KIT, DRV8301,

Hi.

I'm currently designing my own motor controller for the TMS320F28027F and DRV8301. I've been experimenting with the DRV8301-69M-KIT, which has a ControlCard with the much larger F28069M MCU.

The problem that arises from this is that the Trip Zone (TZ) pins are shared with the SPI and SCI peripheral pins on the F28027F. While the F28069M has them separate so it can connect to the DRV8301 with SPI and still connect it's OCTW and FAULT lines to it's TZ pins. I assume after looking at the SPRS523K.pdf that the TZ pins are used to give the ePWM module direct hardware pin interrupt for fault conditions coming from outside so it can disable the PWM outputs.

So the question is, the faults can also be read by SPI from the DRV8301 registers, so should I rather poll it via SPI and see if any faults are present and then software disable the PWM outputs on the F28027F? As I need both the SPI and SCI peripherals on the chip, with SPI going to the DRV8301 so I can configure it, while the SCI is needed for hardware MCU-MCU communication.

  • 0
    TI__Guru** 109730 points
    Is this question for LunchXL-F28027F/ControlCard-F28027F, or for your customized board?
    1. The fault status can be get from DRV8301 status register by SPI communication. and disable PWM output by software. You need to disconnect the SCI pins to DRV8301, if not, the SCI maybe not communicated successfully.
    2. You can set GPIO12/TZ1 for the OCTW and FAULT if it's for customized board.
  • 0 in reply to Yanming Luo
    Intellectual 300 points

    This is for my custom board.

    Yanming said:
    2. You can set GPIO12/TZ1 for the OCTW and FAULT if it's for customized board.

    Yes, of course. As the OCTW and FAULT lines are both open drain in the DRV8301, they can be connected together with a pull-up resistor and then into a Trip Zone input on the GPIO12/TZ1 (pin 47) so that it doesn't interfere with the SPI (pins: 24, 25, 26, 27) or SCI (pins: 1, 48) interfaces. I don't think it really matters even though the OCTW and FAULT are connected together as they should function as a direct hardware interrupt for the ePWM module.

    Yanming said:
    You need to disconnect the SCI pins to DRV8301, if not, the SCI maybe not communicated successfully.

    And just a clarification on the SCI interface, it will be connected to an external MCU for communications and not into the DRV