MC68HC908AS60ACFN FREESCALE [Freescale Semiconductor, Inc], MC68HC908AS60ACFN Datasheet - Page 243

• Manufacturer Part Number: MC68HC908AS60ACFN
• Description: M68HC08 Microcontrollers
• Manufacturer: FREESCALE [Freescale Semiconductor, Inc]

Chapter 21
Programmable Interrupt Timer (PIT)
21.1 Introduction
This chapter describes the Programmable Interrupt Timer (PIT) which is a periodic interrupt timer whose
counter is clocked internally via software programmable options.
PIT.
For further information regarding timers on M68HC08 family devices, please consult the HC08 Timer
Reference Manual, TIM08RM/AD.
21.2 Features
Features of the PIT include:
21.3 Functional Description
Figure 21-1
that can operate as a free-running counter or a modulo up-counter. The counter provides the timing
reference for the interrupt. The PIT counter modulo registers, PMODH–PMODL, control the modulo value
of the counter. Software can read the counter value at any time without affecting the counting sequence.
Freescale Semiconductor
•
•
•
Programmable PIT Clock Input
Free-Running or Modulo Up-Count Operation
PIT Counter Stop and Reset Bits
BUS CLOCK
INTERNAL
shows the structure of the PIT. The central component of the PIT is the 16-bit PIT counter
CSTOP
CRST
MC68HC908AZ60A • MC68HC908AS60A • MC68HC908AS60E Data Sheet, Rev. 6
TIMPMODH:TIMPMODL
16-BIT COMPARATOR
16-BIT COUNTER
PRESCALER
Figure 21-1. PIT Block Diagram
PPS2
PRESCALER SELECT
PPS1
PPS0
Figure 21-1
is a block diagram of the
POIE
POF
INTER-
LOGIC
RUPT
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