MC908AB32CFUE Datasheet, PDF (222/392 Pages) Freescale Semiconductor, Inc – Microcontrollers

Programmable Interrupt Timer (PIT)
13.3 Features
Features of the PIT include the following:
• Programmable PIT clock input
• Free-running or modulo up-count operation
• PIT counter stop and reset bits
13.4 Functional Description
Figure 13-1 shows the structure of the PIT. The central component of
the PIT is the 16-bit PIT counter 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.
INTERNAL
BUS CLOCK
PSTOP
PRST
PRESCALER
PRESCALER SELECT
PPS2 PPS1 PPS0
16-BIT COUNTER
POF
POIE
16-BIT COMPARATOR
PMODH:PMODL
Figure 13-1. PIT Block Diagram
INTERRUPT
LOGIC
Technical Data
222
Programmable Interrupt Timer (PIT)
MC68HC908AB32 — Rev. 1.1
Freescale Semiconductor