H8SSLASH2224 datasheet(527/1071 Pages) RENESAS

527 / 1071 page

Section 12 8-Bit Timers

Rev. 5.00 Aug 08, 2006 page 441 of 982

REJ09B0054-0500

Section 12 8-Bit Timers

The H8S/2258 Group, H8S/2239 Group, and H8S/2238 Group have an on-chip 8-bit timer module

with four channels (TMR_0, TMR_1, TMR_2, and TMR_3) operating on the basis of an 8-bit

counter.

The H8S/2237 Group and H8S/2227 Group have an on-chip 8-bit timer module with two channels

(TMR_0 and TMR_1) operating on the basis of an 8-bit counter.

The 8-bit timer module can be used to count external events and be used as a multifunction timer

in a variety of applications, such as generation of counter reset, interrupt requests, and pulse output

with an arbitrary duty cycle using a compare-match signal with two registers.

12.1

Features

• Selection of clock sources

Selected from three internal clocks (

φ/8, φ/64, and φ/8192) and an external clock.

• Selection of three ways to clear the counters

The counters can be cleared on compare-match A or B, or by an external reset signal.

• Timer output controlled by two compare-match signals

The timer output signal in each channel is controlled by two independent compare-match

signals, enabling the timer to be used for various applications, such as the generation of pulse

output or PWM output with an arbitrary duty cycle.

• Cascading of the two channels

 TMR_0 and TMR_1 cascading

The module can operate as a 16-bit timer using TMR_0 as the upper half and channel

TMR_1 as the lower half (16-bit count mode).

TMR_1 can be used to count TMR_0 compare-match occurrences (compare-match count

mode).

 TMR_2* and TMR_3* cascading

The module can operate as a 16-bit timer using TMR_2 as the upper half and channel

TMR_3 as the lower half (16-bit count mode).

TMR_3 can be used to count TMR_2 compare-match occurrences (compare-match count

mode).

• Multiple interrupt sources for each channel

Two compare-match interrupts and one overflow interrupt can be requested independently.

• Generation of A/D conversion start trigger

Channel 0 compare-match signal can be used as the A/D conversion start trigger.

H8S/2224 Scheda tecnica(PDF) 527 Page - Renesas Technology Corp