C code question for 54102 part

robertrobert — Fri, 30 Mar 2018 17:37:03 GMT

Hi All,

I am using a 54102 processor board from Coridium.

I am using the MakeItC compiler.

I am looking for just a small bit of help with a C statement for this board.

I have reviewed the NXP document for the part and the help I am requesting is a sample C statement that writes to a specific memory address.

That's my question.

Any other C source code that might be available for this part is a great interest to me, but for now I want to program the part by setting register values.

Many thanks,

robert

Re: C code question for 54102 part

bruceeisenhard — Mon, 02 Apr 2018 23:01:44 GMT

At the simplest level in C access to registers is through pointers for ARM processors.

* some_address = some_value; // some_address is defined as a unsigned int pointer type (uint32_t most places)

In header files (old school like me) would define in a header (.h file)

#define LPC_GPIO_DIR * (unint32_t *) 0x1C002000 // GPIO direction for Port 0

#define LPC_GPIO_SET * (unint32_t *) 0x1C002200 // GPIO set for Port 0

And to set say bit 4 high

LPC_GPIO_DIR = (1 << 4); // set pin/bit 4 of Port 0 as output

LPC_GPIO_SET = (1 << 4); // and set that pin high

More modern definitions of registers defines the structure of the set of registers in a header file. So that the same code would be

LPC_GPIO->DIR[0] = (1 << 4); //set pin/bit 4 of the DIR register of Port 0 GPIO structure (group of registers) as output

LPC_GPIO->SET[0] = (1 << 4); // and set that pin high

And some "modern' (obtuse) definitions define them as inline code in a header (start the flame wars- an atrocious practice)

__STATIC_INLINE void Chip_GPIO_WritePortBit(LPC_GPIO_T *pGPIO, uint32_t port, uint8_t pin, bool setting)
{
pGPIO->B[port][pin] = setting;
}

__STATIC_INLINE void Chip_GPIO_SetPinState(LPC_GPIO_T *pGPIO, uint8_t port, uint8_t pin, bool setting)
{
pGPIO->B[port][pin] = setting;
}

LPC MicrocontrollersのトピックC code question for 54102 part

C code question for 54102 part

Re: C code question for 54102 part