SH7616 datasheet(149/935 Pages) RENESAS

149 / 935 page

Section 3 Oscillator Circuits and Operating Modes

Rev. 2.00 Mar 09, 2006 page 123 of 906

REJ09B0292-0200

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.

Note: The values for CL1, CL2, and the damping resistance should be determined after

consultation with the crystal resonator manufacturer.

XTAL

EXTAL

CL2

CL1

Avoid crossing

signal lines

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 VSS/VCC 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.

VSS/VCC pairs

PLL system: 9-12

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

5 V digital system: 157-155, 169-167, 181-179, 191-193, 202-200

SH7616 Datasheet(PDF) 149 Page - Renesas Technology Corp