Periodic Interrupt Timer and Real Time Interrupt (PIT_RTI)
MPC5510 Microcontroller Family Reference Manual, Rev. 1
28-10
Freescale Semiconductor
Preliminary
The counter period can be restarted by first disabling and then enabling the timer with the PITEN register
(see
The counter period of a running timer can be modified by first disabling the timer, setting a new load value,
and then enabling the timer again (see
It is also possible to change the counter period without restarting the timer by writing the TLVAL register
with the new load value. This value will be loaded after the next trigger event (see
Figure 28-9. Stopping and Starting a Timer
Figure 28-10. Modifying Running Timer Period
Figure 28-11. Dynamically Setting a New Load Value
28.4.2
Debug Mode
In debug mode the timers will be frozen—this is intended to aid software development, allowing the
developer to halt the processor, investigate the current state of the system (e.g. the timer values), and then
continue the operation.
28.4.3
Interrupts
The interrupts generated by the PIT are listed in
. Refer to the MCU specification for related
vector addresses and priorities.
p1
p1
Timer Enabled
Disable
Timer
p1
Start Value = p1
Trigger
Event
p1
Re-Enable
Timer
p1
Timer Enabled
Disable
Timer,
Start Value = p1
Trigger
Event
Re-Enable
Timer
p1
Set new
Start Value
p2
p2
p2
p1
p1
Timer Enabled
New Start
Value p2 set
p1
p2
Start Value = p1
p2
Trigger
Event