https://os.mbed.com/cookbook/WatchDog-Timer This link has demonstrated a way to implement Watchdog Timer on Mbed. This library is the library version of that code.

Revision:
2:1b576cfa3f49
Parent:
1:7d0312e56c87
--- a/WatchdogTimer.cpp	Fri Feb 09 11:29:05 2018 +0000
+++ b/WatchdogTimer.cpp	Fri Feb 09 11:32:52 2018 +0000
@@ -9,10 +9,10 @@
     LPC_WDT->WDFEED = 0x55;
 }
 // Load timeout value in watchdog timer and enable
-void WatchdogTimer::kick(float s) {
+void WatchdogTimer::kick(float timeInSecond) {
     LPC_WDT->WDCLKSEL = 0x1;                // Set CLK src to PCLK
     uint32_t clk = SystemCoreClock / 16;    // WD has a fixed /4 prescaler, PCLK default is /4
-    LPC_WDT->WDTC = s * (float)clk;
+    LPC_WDT->WDTC = timeInSecond * (float)clk;
     LPC_WDT->WDMOD = 0x3;                   // Enabled and Reset
     kick();
 }