Freescale Semiconductor ColdFire MCF52210 - Manual (Page 331)

MCF52211 ColdFire® Integrated Microcontroller Reference Manual, Rev. 2
Freescale Semiconductor 20-1
Chapter 20
Programmable Interrupt Timers (PIT0–PIT1)
20.1 Introduction
This chapter describes the operation of the two programmable interrupt timer modules: PIT0–PIT1.
20.1.1 Overview
Each PIT is a 16-bit timer that provides precise interrupts at regular intervals with minimal processor
intervention. The timer can count down from the value written in the modulus register or it can be a
free-running down-counter.
20.1.2 Block Diagram
Figure 20-1. PIT Block Diagram
20.1.3 Low-Power Mode Operation
This subsection describes the operation of the PIT modules in low-power modes and debug mode of
operation. Low-power modes are described in the power management module,
Chapter 8, “Power
Management.” Table 20-1 shows the PIT module operation in low-power modes and how it can exit from
each mode.
Internal Bus
Clock (f
sys
)
16-bit PMRn
16-bit PIT Counter
COUNT = 0
Internal Bus
16-bit PCNTRn
Internal Bus
EN
OVW
DOZE
DBG
Prescaler
PRE[3:0] RLD
PIF
PIE
Load
Counter
To Interrupt
Controller