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Watchdog Timers and Init Code
A change has been made to the start-up code: the code to
disable the watchdog timer has been removed. The code was
in the start-up sequence because it was found that for some
large applications the watchdog timer would trigger whilst
the start-up was happening - ie before main() was reached.
The problem with the disabling code was that the address of
the watchdog timer was hard-coded in the instruction
sequence, which meant that it did not work on MCUs that
used a different address. Rather than try to provide some
complicated, MCU specific, mechanism for disabling the timer
during start-up it was decided to simply remove the code
instead. For most applications this should suffice. If
however an application does need to disable the watchdog
timer during start-up, it can add this function to its code
base:
#include <msp430.h>
static void __attribute__((naked, section(".crt_0042"), used))
disable_watchdog (void)
{
WDTCTL = WDTPW | WDTHOLD;
}
Note - this method can be used to insert *any* commands
into the start-up sequence, not just watchdog timer
disabling code. Also if the number in .crt_0042 is
reduced, the code will execute earlier in the start-up
sequence. If it is increased it will execute later in
the start-up sequence.
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