Oscillator; Connecting A Crystal Resonator - Hitachi H8S/2646 Hardware Manual

Hitachi 16-bit single-chip microcomputer h8s/2646 series

Table of Contents

Bits 1 and 0—Frequency Multiplication Factor (STC1, STC0): The STC bits specify the

frequency multiplication factor of the PLL circuit.

Note: Make this setting so that the clock frequency both before and after multiplication is within

the operating frequency range of the LSI.

Note: A system clock frequency multiplied by the multiplication factor (STC1 and STC0) should

not exceed the maximum operating frequency defined in section 23, Electrical

Characteristics.

Oscillator

A crystal oscillator is used to supply clock pulses.

In either case, the input clock should be from 4 MHz to 20 MHz.

Circuit Configuration: A crystal resonator can be connected as shown in the example in figure

21-2. Select the damping resistance R

crystal should be used.

by the parasitic capacitance of the board and the results of crystal resonator

Figure 21-2 Connection of Crystal Resonator (Example)

Setting prohibited

according to table 21-2. An AT-cut parallel-resonance

are reference values. The capacitance which is used must be decided

(Initial value)

= 10 to 22pF