MC9S12XE-Family Reference Manual , Rev. 1.19
Freescale Semiconductor
525
Chapter 14
Enhanced Capture Timer (ECT16B8CV3)
14.1
Introduction
The HCS12 enhanced capture timer module has the features of the HCS12 standard timer module
enhanced by additional features in order to enlarge the field of applications, in particular for automotive
ABS applications.
This design specification describes the standard timer as well as the additional features.
The basic timer consists of a 16-bit, software-programmable counter driven by a prescaler. This timer can
be used for many purposes, including input waveform measurements while simultaneously generating an
output waveform. Pulse widths can vary from microseconds to many seconds.
A full access for the counter registers or the input capture/output compare registers will take place in one
clock cycle. Accessing high byte and low byte separately for all of these registers will not yield the same
result as accessing them in one word.
14.1.1
Features
•
16-bit buffer register for four input capture (IC) channels.
•
Four 8-bit pulse accumulators with 8-bit buffer registers associated with the four buffered IC
channels. Configurable also as two 16-bit pulse accumulators.
•
16-bit modulus down-counter with 8-bit prescaler.
•
Four user-selectable delay counters for input noise immunity increase.
14.1.2
Modes of Operation
•
Stop — Timer and modulus counter are off since clocks are stopped.
Table 14-1. Revision History
Revision
Number
Revision Date
Sections
Affected
Description of Changes
V03.02
03 Apr 2007
- Removed redundant memory map table, corrected MCCNT[9] to MCCNT[0]
in register summary sheet (5 of 6), Removed Memory Map table (since the
information is redundant) in register summary figure.
V03.03
14 Sep 2007
- Corrected typo OPCD -> OCPD
V03.04
08 May 2008
- Enhanced pulse accumulator B description.
V03.05
09 Sep 2008
Fixed a typo and refined a statement pertaining to switch between I/O and
timer functionlality.
Because
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an
order
from
the
United
States
International
Trade
Commission,
BGA-packaged
product
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part
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available
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for
import
or
sale
in
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prior
to
September
2010:
S12XE
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