Rabbit 3000 User Manual page 146

rupts are enabled, then the first interrupt may take place at an unknown time. Similarly, if the
timer output is being used to drive the clock for a parallel port or serial port, the first clock
may come at a random time. If a periodic clock is desired, it is probably not important when
the first clock takes place unless a phase relationship is desired relative to a different timers.
A phase relationship between two timers can be obtained in several ways. One way is to
set both reload registers to zero and to wait long enough for both timers to reload (maxi-
mum 256 clocks). Then both timers' reload registers can be set to new values before or
after both are clocked.
138 Rabbit 3000 Microprocessor