Its always the simple things that get you.
During initialization I init the watchdog as follows....
Chip_WWDT_SetTimeOut(LPC_WWDT, WDT_OSC / 1); // 1 second till reset
Then as the program is running I do a ...
Chip_WWDT_Feed(LPC_WWDT); // every 10 mSec
The problem is that it always resets after 1 second. In the debugger, I see the WWDT_Feed() , loads the 0xAA, then 0x55 in plenty of time but the TV register doesn't get set back to the TC setting.
The LPC4078 seems only to have the dedicated watchdog oscillator and it is taking about 1 second to reset.