MC9S12XE-Family Reference Manual , Rev. 1.07
Freescale Semiconductor
539
Chapter 14
Enhanced Capture Timer (ECT16B8CV3)
14.1
Revision History
14.2
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.
14.2.1
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.
Version
Number
Revision
Date
Effective
Date
Author
Description of Changes
02.03
12-Aug-04
12-Aug-04
Included OC initialization description in section 4.2.2 and
updated version on cover sheet.
Added register OCPD(1.4.2.25) to isolate OCx from pin logic and
also updated the information of OC initialization in section 4.2.2.
Verbage modified for OCPD and 1.4.1.2 sections
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.
03.00
15-Oct-05
15-Oct-05
03.01
21 Nov 05
21 Nov 05
03.01
03 Apr 07
12 Apr 07