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CCS/MSP430F5659: Fatfs power_on() and power_off() support

Part Number: MSP430F5659

Tool/software: Code Composer Studio

I am working on implementing the FatFs file system with a msp430f5659. I noticed that the example project most closely related to what I'm doing (MSP-EXP430F5529 User Experience) doesn't have support for removing power to the SD card (I have worked with the Tiva implementation that handles this using disk_ioctl()). For my application, a FET supplies VDD power to the SD card. Is there a preexisting example that supports this? I would prefer to not start hacking on the files system unless I have to.

Thanks,

  • Hi Sheldon,

    The function disk_ioctl() is available in MSP-EXP430F5529 User Experience, if this is not work for removing power to the SD card, maybe you need to read the code in TIVA and understand how to control the power for SD card then implement to MSP430.

    regards
    KC
  • Dear Kc,

    The disk_ioctl() function found in MSP-EXP430F5529 is where I started. It has a very limited set of instructions compared with the Tiva variant. After further inspection, I am also concerned that the Tiva variant doesn't actually kill the power (Even though the logic is in place in disk_ioctl). When I searched for all of the function calls of disk_ioctl(), I saw that none pass in the parameter CTRL_POWER. This appears to be a fundamental omission of the ability to turn the power off in the TI fatfs implementation. Can you please verify if I am correct here?

  • Hi Sheldon,

    From the schematic of MSP-EXP430F5529, the power for SD card is VCC which can not be control to switch on/off, if you want to kill the power for SD card need additional power control circuit.

    regards
    KC
  • Hi,

    The FatFS have nothing to do with power management, however SD-Card standard supports commands for deep sleep and power off modes. TI made an effort for 'proof of concept' to support FatFS on ULP devices. Any additional functions and optimizations (like high speed real-time buffered transmission) should be done by a developer. Some additional implementations of FatFS requires commercial paid licenses to Microsoft, and some additional information on how to implement specific low-power modes on SD-Card requires acquire additional paid licensing from SD Card Association.

    Hope this clarify,

    Regards,

    Alexey

  • Hi Alexey,

    Thanks a lot for clarify this.

    regards
    KC
  • Dear KC Xu,

    I guess I should have clarified. I'm not using any of your development boards, just the examples for them. My boards all have the additional power management circuitry on board. I was just hoping that the examples had power management integrated in the abstraction layers, but Alexey gave a good example as to why this isn't the case. I gave up my search about a month ago and integrated my own power management after I finish reading and writing to files.

    Thanks guys,

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