SH7615 Datasheet, PDF (161/925 Pages) Renesas Technology Corp – 32-Bit RISC Microcomputer SuperH
RISC engine Family/SH7600 Series

3.2.7 Notes on Board Design
When Using an External Crystal Oscillator: Place the crystal resonator, capacitors CL1 and
CL2, and damping resistor R close to the EXTAL and XTAL pins. To prevent induction from
interfering with correct oscillation, use a common grounding point for the capacitors connected to
the resonator, and do not locate a wiring pattern near these components.
Figure 3.5 shows an example of the oscillator circuit. This is a sample oscillator circuit and in the
actual system, the values shown in the figure are affected by the environment such as noise, power
supply characteristics, or wiring patterns. These values cannot be guaranteed and should be used
as reference values. To determine the optimum oscillator circuit constants for the user system,
please consult with the crystal resonator manufacturer.
Avoid crossing
signal lines
CL1
CL2
EXTAL
R
XTAL
CL1, CL2 = 20 to 22 pF
R=0Ω
Oscillation frequency:
15.625 MHz
Crystal resonator:
HC-49/u manufactured by
KYUSHU DENTSU CO., LTD.
Note: The values for CL1, CL2, and the damping resistance should be determined after
consultation with the crystal resonator manufacturer.
Figure 3.5 Points for Attention when Using Crystal Resonator
Bypass Capacitors: As far as possible, insert a laminated ceramic capacitor of 0.01 to 0.1 µF as a
bypass capacitor for each V_SS/V_CC pair. Mount the bypass capacitors as close as possible to the
LSI power supply pins, and use components with a frequency characteristic suitable for the LSI
operating frequency, as well as a suitable capacitance value.
1. V_SS/V_CC pairs for FP-208C and FP-208CV
a. PLL system: 9-12
b. 3 V digital system: 20-18, 26-22, 35-33, 45-42, 52-50, 60-58, 61-67, 69-66, 78-76,
79-81, 91-89, 101-99, 112-109, 113-110, 114-116, 130-132, 149-146,
150-147
c. 5 V digital system: 157-155, 169-167, 181-179, 191-193, 202-200
Rev. 2.00, 03/05, page 123 of 884