Freescale Semiconductor MPC5604B - Chapter 5 eMIOS: Enhanced Modular I;O Subsystem

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Chapter 4
Timer Modules
1.
Introduction
There are various timer-like peripherals available in this microcontroller with different
characteristics and uses. Here’s a list of timer modules with brief descriptions:
 System Timer Module (STM): A 32-bit running-up counter, clocked by the system
clock. It has four 32-bit compare channels with individual interrupts. Useful for
measuring code execution time (clock cycles).
 Periodic Interrupt Timer (PIT): Made of six timers clocked by the system clock. They
are 32-bit count-down timers; they have to be initialised with a start value. Reaching
0 and restarting triggers an interrupt.
 Enhanced Modular I/O Subsystem (eMIOS): This module will not be explained in this
chapter but the next chapter will be solely dedicated to it. It is useful for
measurements and generating PWM.
 Real Time Clock/Autonomous Periodic Interrupt (RTC/API): 32-bit counter, can
measure up to 1.5 Months with 1ms resolution. Can trigger interrupts and wakeup
events on match. API module can generate periodic interrupts while RTC keeps
counting.
Figure 34 : Interaction between some timers and other peripherals (R.M. Rev8 – Fig. 24-1)