taku hachisu / Watchdog

Watchdog timer for LPC1549

Watchdog.cpp

Committer:
takuhachisu
Date:
2017-11-10
Revision:
0:35b88129a223
Child:
2:c72a3d9002d5

File content as of revision 0:35b88129a223:

/**
 * @file    Watchdog.cpp
 * @brief   Watchdog for LPC1549
 * @author  taku hachisu
 * @date    2017/11/02
 */

#include "mbed.h"
#include "Watchdog.h"

Watchdog::Watchdog(int ms)
{
    timeOutFlag = (LPC_WWDT->MOD >> 2) & 1;
    LPC_SYSCON->SYSAHBCLKCTRL0 |= (1 << 22);
    LPC_SYSCON->PDRUNCFG &= ~(1 << 20);
    LPC_SYSCON->STARTERP0 |= 1;
    uint32_t clk = 503000 / 4;                          // LPC1549's watchdog oscillator is fixed to 503 kHz
    LPC_WWDT->TC = ((float)ms * (float)clk) / 1000;
    LPC_WWDT->MOD = 0x03;
    feed();
}

void Watchdog::feed()
{
    LPC_WWDT->FEED = 0xAA;
    LPC_WWDT->FEED = 0x55;
}