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TMS320F28377D: About EM1DQM in EMIF setting of TMS320F28377D

Takayuki Mori
Prodigy 60 points
Part Number: TMS320F28377D


Now, I am currently considering using the TMS320F28377D and have the following question:

I will be using EMIF1 as the interface with external asynchronous 16-bits memory.

I will not be using the EM1DQM signal in particular.
Is there a problem?

In what cases will the EM1DQM signal be necessary?

If I do not need to use the EM1DQM signal, can I leave it as a GPIO and leave it unconnected, without assigning a function to EM1DQM in the GPIO MUX settings?

Or, even if I will not be using the EM1DQM signal, do I still need to set it to EM1DQM in the GPIO MUX settings?
In that case, how should I handle the EM1DQM pin?
(Specifically, should I set the MUX setting for GPIO88 to 0: GPIO or 3: EM1DQM0?
Also, I plan to use GPIO89-91 for other GPIO functions or SCI. Will this be a problem?)

Regards,

T. Mori

  • +1
    TI__Mastermind 19341 points

    Hi Takayuki-san,

    Since C2000 is 16-bit addressable and you are interfacing with 16-bit memory, it's not necessary to use DQM signal, see following note: Dynamic control of the byte enable signals is not required for 16-bit memories because the C28x is 16-bit word addressable. The memory byte enable signals can be tied low (permanently enabled) for 16-bit memories. Byte enable signals for 32-bit memories can also be tied low if 16-bit writes and reads are not used.

    It's only necessary to use DQM if you are interfacing memory device where you need to select a specific byte size other than the addressable size. You can use signal as a general purpose IO for any other purpose and there will not be an issue

    Regards,

    Peter

  • 0 in reply to Peter Luong1
    Prodigy 60 points

    Hi Peter,

    Thank you for your reply!

    I understand that using DQM is not necessary for 16-bit memory access,

    and that it is okay to set pins for other functions such as GPIO.

    Regards,

    T. Mori