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TMS320F28075: Can I use MMOV32 to update DBFED and DBFEDHR simultaneously?

Long MaX
Intellectual 270 points
Part Number: TMS320F28075

Hi,

DBFED and DBFEDHR are two different 16 bit registers whose addresses are adjacent. Can I use only a MMOV32 instruction to update the values of the two registers or must I use two MMOV16 instructions to update them consecutively?

Thanks a lot for any answer!

  • 0
    TI__Expert 5940 points
    Hello,

    I believe that the functionality you're describing is possible as those registers are both memory-mapped and adjacent to each other.
    The below MMOV32 instruction should achieve this, where mem32 is the register address and MRa has the value for update. Please write back if you experience an issue.
    MMOV32 mem32, MRa

    Unless your project needs require assembly programming, there's a CLA C compiler available as well so programming in C for the CLA is an option you can consider, just so you're aware.

    Regards,
    Elizabeth
  • 0 in reply to Elizabeth Joy
    Intellectual 270 points
    Hello,

    Could you please tell me why Texas Instruments devides DBFED into two seperate 16-bit registers DBFED and DBFEDHR while there is only one 32-bit register for CMPA?

    Best regards,
    Long
  • 0 in reply to Long MaX
    TI__Expert 5940 points
    Hi Long,

    The main reason for CMPA (and CMPB) being 1 32-bit register that includes the HR field is so that the CMPA/CMPB can be efficiently updated in a control loop with 1 write (instead of 2). The compare registers are more likely to be modified in every control loop as duty-cycle needs to be adjusted frequently in many applications, while dead-band module doesn't have this requirement as often.

    The other reason is that as the EPWM types (types 0-4, where type 4 EPWM is on F2807x) evolved with additional functionality, the high-resolution registers for different submodules had to be retrofitted in the design/address space where possible and still allow some portability between EPWM types.

    Regards,
    Elizabeth
  • 0 in reply to Elizabeth Joy
    Intellectual 270 points
    Hi Elizabeth,

    Thank you for your explications.

    Best regards,
    Long