Usage Notes; Note On Resonators; Notes On Board Design; Figure 5.13 Example Of Incorrect Board Design - Renesas H8 Series Hardware Manual

Section 5 Clock Pulse Generators
5.7

Usage Notes

5.7.1

Note on Resonators

Resonator characteristics are closely related to board design and should be carefully evaluated by
the user, referring to the examples shown in this section. Resonator circuit parameters will differ
depending on the resonator element, stray capacitance of the PCB, and other factors. Suitable
values should be determined in consultation with the resonator element manufacturer. Design the
circuit so that the resonator element never receives voltages exceeding its maximum rating.
5.7.2

Notes on Board Design

When using a crystal resonator (ceramic resonator), place the resonator and its load capacitors as
close as possible to pins OSC1 and OSC2. Other signal lines should be routed away from the
oscillator circuit to prevent induction from interfering with correct oscillation (see figure 5.13).
Rev. 3.00 Sep. 14, 2006 Page 84 of 408
REJ09B0105-0300
Prohibited
PC0/OSC1
PC1/OSC2/CLKOUT

Figure 5.13 Example of Incorrect Board Design

Signal A Signal B
C
C
1
2