HD6417144 RENESAS [Renesas Technology Corp], HD6417144 Datasheet - Page 102

• Manufacturer Part Number: HD6417144
• Description: 32-Bit RISC Microcomputer SuperHTM RISC engine Family/SH7144 Series
• Manufacturer: RENESAS [Renesas Technology Corp]

4. Clock Pulse Generator
4.3
4.3.1
A sufficient evaluation at the user’s site is necessary to use the LSI, by referring the resonator
connection examples shown in this section, because various characteristics related to the crystal
resonator are closely linked to the user’s board design. As the oscillator circuit's circuit constant
will depend on the resonator and the floating capacitance of the mounting circuit, the value of each
external circuit’s component should be determined in consultation with the resonator
manufacturer. The design must ensure that a voltage exceeding the maximum rating is not applied
to the oscillator pin.
4.3.2
Measures against radiation noise are taken in this LSI. If further reduction in radiation noise is
needed, it is recommended to use a multiple layer board and provide a layer exclusive to the
system ground.
When using a crystal resonator, place the crystal resonator and its load capacitors as close as
possible to the XTAL and EXTAL pins. Do not route any signal lines near the oscillator circuitry
as shown in figure 4.5. Otherwise, correct oscillation can be interfered by induction.
Rev.4.00 Mar. 27, 2008 Page 58 of 882
REJ09B0108-0400
Usage Notes
Note on Crystal Resonator
Notes on Board Design
Figure 4.5 Cautions for Oscillator Circuit Board Design
Avoid
C
C
L2
L1
Signal A Signal B
XTAL
EXTAL
This LSI