Lpc2000

--- In lpc2000@yahoogroups.com, "philips_apps" <philips_apps@y...> wrote:
> What LPC2000 part are you using? Is it a 48-pin (LPC2104/5/6) or 
> 64/144-pin (LPC2114/2124/2212/2214 & LPC2119/2129/2194/2292/2294) 
> device?

It is a 64 pin device.  LPC2124 to be precise.  I also have a
LPC2106 circuit, and the watchdog seems to work okay on that.

I stripped the code down to a minimal example.  The assembly
stub has only two instructions (initialize sp, and jump to
main()).  Interrupts are not enabled.  On the LPC2106 the
output pin goes low for a few seconds, toggles for a few
seconds, and then repeats as the chip is reset by the watchdog.
On the LPC2124, the cycle only happens once.  Then the chip
freezes up and requires an external reset.

----------------------------------------------------------
int
main(void) {
  int i;
  
  IO0DIR = 0x00000040;
  IO0CLR = 0x00000040;
  // Ground the pins for a few seconds
  for (i = 20000000; --i >= 0;) { 
    continue;
  }
  WDTC   = 20000000;
  WDMOD  = 0x03;
  WDFEED = 0xaa;
  WDFEED = 0x55;
  // Toggle until the watchdog reset triggers
  for (;;) {	
    IO0CLR = 0x00000040;
    IO0SET = 0x00000040;
  }
}
----------------------------------------------------------

> --- In lpc2000@yahoogroups.com, "bobbruce000" <bobbruce000@y...> 
> wrote:
> > I am having problems recovering after a watchdog reset.
> > I enable the watchdog, then to test it, I put the cpu
> > into a loop, toggling a pin connected to a logic probe.
> > If I set the reset to, say, 3 seconds, then right
> > on time the toggling stops.  So the watchdog reset
> > is triggered.
> > 
> > But the processor never comes back to life.  I have to
> > ground the reset pin to get it to come back.  How does
> > a watchdog reset differ from a hardware reset?  Are there
> > some components (PLL?, UART?, TIMER?) that don't get
> > reset?