HD6433308 HITACHI [Hitachi Semiconductor], HD6433308 Datasheet - Page 167

• Manufacturer Part Number: HD6433308
• Description: Hitachi Single-Chip MicroComputer
• Manufacturer: HITACHI [Hitachi Semiconductor]

7.1 Overview
The H8/330 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. One application of
the 8-bit timer module is to generate a rectangular-wave output with an arbitrary duty factor.
7.1.1 Features
The features of the 8-bit timer module are listed below.
• Selection of four clock sources
• Selection of three ways to clear the counters
• Timer output controlled by two time constants
• Three independent interrupts
7.1.2 Block Diagram
Figure 7-1 shows a block diagram of one channel in the 8-bit timer module. The other channel is
identical.
The counters can be driven by an internal clock signal (Ø/8, Ø/64, or Ø/1024) or an external
clock input (enabling use as an external event counter).
The counters can be cleared on compare-match A or B, or by an external reset signal.
The timer output signal in each channel is controlled by two independent time constants,
enabling the timer to generate output waveforms with an arbitrary duty factor.
Compare-match A and B and overflow interrupts can be requested independently.
Section 7. 8-Bit Timers
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