Datasheet

Section 13 8-Bit Timers (TMR)
(This function is not available in the H8S/2695)
R01UH0166EJ0600 Rev. 6.00 Page 661 of 1434
Mar 02, 2011
H8S/2633 Group, H8S/2633 F-ZTAT
TM
,
H8S/2633R F-ZTAT
TM
, H8S/2695
Section 13 8-Bit Timers (TMR)
(This function is not available in the H8S/2695)
13.1 Overview
The H8S/2633 Group includes an 8-bit timer module with four channels (TMR0, TMR1, TMR2,
and TMR3). Each channel has an 8-bit counter (TCNT) and two time constant registers (TCORA
and TCORB) that are constantly compared with the TCNT value to detect compare match events.
The 8-bit timer module can thus be used for a variety of functions, including pulse output with an
arbitrary duty cycle.
13.1.1 Features
The features of the 8-bit timer module are listed below.
• Selection of four clock sources
⎯ The counters can be driven by one of three internal clock signals (φ/8, φ/64, or φ/8192) or
an external clock input (enabling use as an external event counter)
• 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 control by a combination of two compare match signals
⎯ The timer output signal in each channel is controlled by a combination of two independent
compare match signals, enabling the timer to generate output waveforms with an arbitrary
duty cycle or PWM output
• Provision for cascading of two channels
⎯ Operation as a 16-bit timer is possible, using channel 0 (channel 2) for the upper 8 bits and
channel 1 (channel 3) for the lower 8 bits (16-bit count mode)
⎯ Channel 1 (channel 3) can be used to count channel 0 (channel 2) compare matches
(compare match count mode)
• Three independent interrupts
⎯ Compare match A and B and overflow interrupts can be requested independently
• A/D converter conversion start trigger can be generated
⎯ Channel 0 compare match A signal can be used as an A/D converter conversion start
trigger
• Module stop mode can be set
⎯ As the initial setting, 8-bit timer operation is halted. Register access is enabled by exiting
module stop mode