This blog post explains how to interface DAC with LPC4088 based cortex m4 development board

Procedure to interface DAC with Cortex M4

1. Configure Pin P0.26 for DAC using IOCON_P0_26
2. Enable DAC
3. Set the Maximum current output as default (700uA)
4. Write the sample DAC values in DAC data register.

C source code to interface DAC with Cortex M4

#include "LPC407x_8x_177x_8x.h"

void init_dac(void);
void Write_DAC(unsigned int dacval);
void delay_ms(long ms) ;

int main(void)
{
		init_dac();

		while(1)
		{
				Write_DAC(0x3FF);
				delay_ms(1);
				Write_DAC(0);
				delay_ms(1);
		}
}

void init_dac(void)
{
	
	//1.Configure Pin P0.26 for DAC using IOCON_P0_26
	//2.Enable DAC (bit 16)
	  LPC_IOCON->P0_26 =  (2<<0) | (1<<16);        	/* Pin P0.26 used as DACDOUT */

	//3.Set the Maximum current output as default (700uA)
	  LPC_DAC->CR = 0;								
													
}

//4.Write the sample DAC values in DAC data register
void Write_DAC(unsigned int dacval)
{
	  LPC_DAC->CR = (dacval<<6);
}

void delay_ms(long ms) 					// delay 1 ms per count @ CCLK 120 MHz
{
		long i,j;
		for (i = 0; i < ms; i++ )
		for (j = 0; j < 26659; j++ );
}