HD64F2149 Datasheet, PDF (331/1035 Pages) Renesas Technology Corp – Hitachi 16-Bit Single-Chip Microcomputer

Section 11 16-Bit Free-Running Timer
11.1 Overview
The H8S/2169 or H8S/2149 has a single-channel on-chip 16-bit free-running timer (FRT) module
that uses a 16-bit free-running counter as a time base. Applications of the FRT module include
rectangular-wave output (up to two independent waveforms), input pulse width measurement, and
measurement of external clock periods.
11.1.1 Features
The features of the free-running timer module are listed below.
• Selection of four clock sources
 The free-running counter can be driven by an internal clock source (ø/2, ø/8, or ø/32), or an
external clock input (enabling use as an external event counter).
• Two independent comparators
 Each comparator can generate an independent waveform.
• Four input capture channels
 The current count can be captured on the rising or falling edge (selectable) of an input
signal.
 The four input capture registers can be used separately, or in a buffer mode.
• Counter can be cleared under program control
 The free-running counters can be cleared on compare-match A.
• Seven independent interrupts
 Two compare-match interrupts, four input capture interrupts, and one overflow interrupt
can be requested independently.
• Special functions provided by automatic addition function
 The contents of OCRAR and OCRAF can be added to the contents of OCRA automatically,
enabling a periodic waveform to be generated without software intervention.
 The contents of ICRD can be added automatically to the contents of OCRDM × 2, enabling
input capture operations in this interval to be restricted.
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