void init_pwm()
{
  // PWMW[ɓdƃNbN
  *PCONP = *PCONP | (1 << 6);
  *PCLKSEL0 = *PCLKSEL0 | (1 << 12); // PCLK_PWM1[13:12] <= "01"

  // o̓s̃[hZbg
  *GPIO_PINSEL3 = *GPIO_PINSEL3 | (2 << 4); // PINSEL3[5:4] <= "10"
  
  // PWMW[̏ݒs
  *PWM1MCR = *PWM1MCR | (1 << 0) | (1 << 1); // }b`犄ݔ
  *PWM1PCR = *PWM1PCR | (1 << 9); // PWMENA1
  *PWM1MR0 = 1000;
  *PWM1MR1 = 0;

  // PWM݂̊݃Rg[ɓo^
  *VIC_IntEnable = (1 << 8); // PWMMatch0-6Ŋ݂𔭐
  __enable_interrupt();
  __enable_irq();

  // PWMW[̓Jn
  *PWM1TCR = *PWM1TCR | (1 << 0) | (1 << 3);
}
