Handling Of X1 And X2 Pins; Usage Notes; Notes On Resonator; Notes On Board Design - Renesas H8S Series Hardware Manual

23.8

Handling of X1 and X2 Pins

The X1 and X2 pins should be open, as shown in figure 23.9.
23.9

Usage Notes

23.9.1

Notes on Resonator

Since all kinds of characteristics of the resonator are closely related to the board design by the
user, use the example of resonator connection in this document for only reference; be sure to use
an resonator that has been sufficiently evaluated by the user. Consult with the resonator
manufacturer about the resonator circuit ratings that vary depending on the stray capacitances of
the resonator and installation circuit. Make sure the voltage applied to the oscillation pins do not
exceed the maximum rating.
23.9.2

Notes on Board Design

When using a crystal resonator, the crystal resonator and its load capacitors should be placed as
close as possible to the XTAL and EXTAL pins. Other signal lines should be routed away from
the oscillator to prevent inductive interference with correct oscillation as shown in figure 23.10.

Figure 23.10 Note on Board Design of Oscillator Section

Figure 23.9 Handling of X1 and X2 Pins

Signal A
Prohibited
C
L2
C
L1
Section 23 Clock Pulse Generator
X1 Open
X2 Open
Signal B
This LSI
XTAL
EXTAL
Rev. 3.00 Jul. 14, 2005 Page 857 of 986
REJ09B0098-0300