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Compiler/TMS320F280049C: Could use HWREGH() function to replace driverlib code to accelerate code execution time

Rayna Wang
Expert 3680 points
Part Number: TMS320F280049C

Tool/software: TI C/C++ Compiler

Hi Expert,

In order to accelerate code execution time, could we use  HWREGH() instead of bit field function to replace driverlib code?

Thanks!

Rayna

  • 0
    TI__Mastermind 33415 points

    Hi Rayna,

    There are multiple ways of accessing peripheral registers - direct register access, driver library (DriverLib), and bitfields.

    The following diagram indicates the comparison between the different ways. HWREG can be used to increase the code efficiency by accessing the registers directly, however DriverLib is the preferred model.  Refer this link for more details

    https://software-dl.ti.com/C2000/docs/software_guide/c2000ware/drivers.html

    https://software-dl.ti.com/C2000/docs/software_guide/_images/RegAccess.png

    Best Regards

    Siddharth

  • 0 in reply to Siddharth Deshpande
    TI__Expert 3680 points

    Hi Siddharth,

    I have tested the execution time of below code by CCS clk, and have some confusion.

    EPWM_enableValleyCapture(EPWM1_BASE); // 68 * sysclk

    ASSERT(EPWM_isBaseValid(EPWM3_BASE));  //54 * sysclk
    EALLOW;
    HWREGH(EPWM3_BASE + EPWM_O_VCAPCTL) |= EPWM_VCAPCTL_VCAPE; // 12 * sysclk
    EDIS;

    Why "ASSERT(EPWM_isBaseValid(EPWM3_BASE));" need so much time to execute, and could this line be deleted if time limited?

    Thanks!

    Rayna

  • 0 in reply to Rayna Wang
    TI__Mastermind 33415 points

    Rayna,

    The assert macro is required by the ANSI standard for C.  It tests the given expression, and if it is zero, a message is output and the program exits. 

    The TI implementation of assert calls the standard C I/O functions fputs and fflush to output the message. These functions, in turn, call many other functions in the compiler RTS library. Hence it takes more time.

    Also ,assertions should never stay in production code. It should be changed to a run time error check, i.e. something coded like this: if( condition != expected ) throw exception. So you can replace that with an expression.

    Best Regards

    Siddharth