This code configures the LPC1768 microcontroller's PWM peripheral to generate a pulse width modulated signal on pin PWM1.5. It initializes the PWM timer and match registers, enables the PWM output, and then uses a for loop to incrementally change the duty cycle of the PWM signal from 10% to 100% over 10 steps, pausing 1 second between each step. This allows the user to see the PWM output change frequency smoothly over time.

1. Interfacing Diagram:

2. Code:
#include<stdio.h>
#include "LPC1768_Includes.h"
void delay(unsigned int time)
{
unsigned int j=0,i=0;
for (j=0;j<time;j++)
for (i=0;i<20000;i++);
}
int main()
{
unsigned int periods=100000,i;
PINSEL3=0x00020000; //PWM1.5
PCONP=1<<6; //PCPWM1 PWM1 power/clock control bit.
PWM1CTCR=0x00000000; // Timer Mode, PCAP1.0,
PWM1PR=0x0000; // Prescale Register. The TC is incremented every PR+1 cycles of PCLK
PWM1MCR=0x00000002; //Reset on PWMMR0: the PWMTC will be reset if PWMMR0 matches it.
PWM1MR0=periods; // Match Register 0.
PWM1PCR=0x00002000; // The PWM5 output enabled.
PWM1TCR=0X00000009; // PWM Timer Counter,PWM Prescale Counter enabled , PWM mode is enabled
while(1)
{
for (i=10;i>0;i--)
{
PWM1MR5=i*periods/10;
PWM1LER=0x00000020; //Enable PWM Match 5 Latch (writing 1)

3. delay(1000);
}
}
}
Output: