D12320VF25IV Datasheet, PDF (589/1304 Pages) Renesas Technology Corp – Old Company Name in Catalogs and Other Documents

Section 12 8-Bit Timers
Section 12 8-Bit Timers
12.1 Overview
The chip includes an 8-bit timer module with two channels (TMR0 and TMR1). 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.
12.1.1 Features
The features of the 8-bit timer module are listed below.
• Seleyction 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)
• Seleyction of three ways to clear the counters
The counters can be cleared on compare match A or B, or by an external reset signal
• Timyer 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 for the upper 8 bits and channel 1
for the lower 8 bits (16-bit count mode)
⎯ Channel 1 can be used to count channel 0 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
Rev.6.00 Sep. 27, 2007 Page 557 of 1268
REJ09B0220-0600