TMS320C6748: The functionality of the HWREG function

?? ?

Part Number: TMS320C6748

I have recently started working with TMS320C6748, and I am troubled by this statement in the routine about SPI. I cannot understand the role of HWREG and what the overall meaning of this function is. I hope you can answer for me.

void SPIReset(unsigned int baseAdd)
{
HWREG(baseAdd + SPI_SPIGCR0) = ~(SPI_SPIGCR0_RESET);
}

4 个月前

+1 Gary Lu 4 个月前

TI__Mastermind 27060 points

The code you've provided is written in C and appears to be a function named SPIReset, which takes an unsigned integer baseAdd as a parameter. This function seems to reset the SPI module by writing a value to the SPIGCR0 register.

The HWREG macro is often used in embedded systems programming to access and manipulate hardware registers. It is typically defined as a macro that allows direct access to memory-mapped hardware registers. In this context, HWREG is being used to access the memory address corresponding to the baseAdd offset by SPI_SPIGCR0, and then a value is written to that memory address.

The expression HWREG(baseAdd + SPI_SPIGCR0) is accessing the memory-mapped register at the address baseAdd + SPI_SPIGCR0, and then the value ~(SPI_SPIGCR0_RESET) is being assigned to that register.

The ~(SPI_SPIGCR0_RESET) seems to be a bitwise negation of the value SPI_SPIGCR0_RESET. The purpose of this code is likely to reset specific bits or flags within the SPIGCR0 register.

0 ?? ? 4 个月前回复 Gary Lu

Prodigy 130 points

I can understand it as follows: after executing this function, the register with address (baseAdd+SPI-SPIGCR0) will be assigned a value of~(SPI-SPIGCr0_ RESET), right?

+1 Gary Lu 4 个月前回复 ?? ?

TI__Mastermind 27060 points

Yes, that is correct. After executing the "SPIReset" function, the register at the address (baseAdd + SPI_SPIGCR0) will be assigned the value of ~(SPI_SPIGCR0_RESET). The tilde (~) operator performs a bitwise negation, so it will invert the bits of the value SPI_SPIGCR0_RESET and then assign the result to the specified register. This operation is likely intended to reset or initialize the SPI control register to a specific value.