Compiler/MSP432P401R: drivelib question

Armando Ferreira

Expert 1945 points

Part Number: MSP432P401R

Tool/software: TI C/C++ Compiler

Hello,

I am trying to made a code I2C to cmsis registers, but i have some problems, I pick up the I2C.c file on the drivelib, and now i try transform the code to cmsis register, but I don't understand some pieces, can anyone help me? I litle example how can transform this piece of code:

  //If interrupts are not used, poll for flags
    if (!BITBAND_PERI(EUSCI_B_CMSIS(moduleInstance)->IE, EUSCI_B_IE_TXIE0_OFS))
    {
        //Poll for transmit interrupt flag.
        while
            (!BITBAND_PERI(EUSCI_B_CMSIS(moduleInstance)->IFG, EUSCI_B_IFG_TXIFG0_OFS))
            ;
    }

    //Send single byte data.
    EUSCI_B_CMSIS(moduleInstance)->TXBUF = txData;

over 7 years ago

0 Amit Ashara over 7 years ago

TI__Guru**** 244380 points

Hello User,

What is that you are not able to understand?

0 Armando Ferreira over 7 years ago in reply to Amit Ashara

Expert 1945 points

HI Amit Ashara ,

I don't understand the code "BITBAND_PERI", if i have to transform the code to cmsis I would put it in the following way...

if(EUSCI_B0->IE |= EUSCI_B_IE_TXIE0){

while(!(EUSCI_B0->IFG|= EUSCI_B_IFG_TXIFG0));

}

    //Send single byte data.
    EUSCI_B0->TXBUF = txData;

0 Amit Ashara over 7 years ago in reply to Armando Ferreira

TI__Guru**** 244380 points

Hello User,

What you are trying to do is to perform an operation of logical OR rather than checking for a boolean condition. It may not work and rather have some unintended results. Why is that you want to do the operation in CMSIS when the DriverLib API already exists.

0 Armando Ferreira over 7 years ago in reply to Amit Ashara

Expert 1945 points

The problem is, all my code was writen CMSIS register, soo I need or I have to integrate this I2C lib in cmsis to work with my all code. And this is my difficulty
I dont understand the BITBAND_PERI, what he does

0 Amit Ashara over 7 years ago in reply to Armando Ferreira

TI__Guru**** 244380 points

Hello User,

You should have looked at the definition for BITBAND_PERI

/* peripherals with 8 bit or 16 bit register access allow only 8 bit or 16 bit bit band access, so cast to 8 bit always */
#define BITBAND_PERI(x, b) (*((__IO uint8_t *) (BITBAND_PERI_BASE + (((uint32_t)(volatile const uint32_t *)&(x)) - PERIPH_BASE)*32 + (b)*4)))

0 Armando Ferreira over 7 years ago in reply to Amit Ashara

Expert 1945 points

thank you Amit Ashara

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Compiler/MSP432P401R: drivelib question