Renesas Stereo System SH7709S Manual De Usuario

Rev. 5.00, 09/03, page 220 of 760

When Using an External Crystal Resonator: Place the crystal resonator, capacitors CL1 and
CL2 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 and CL2 should be determined after 
 

consultation with the crystal manufacturer.

XTAL

EXTAL

SH7709S

CL2

CL1

Avoid crossing 
signal lines

Decoupling Capacitors: Insert a laminated ceramic capacitor of 0.1 to 1 

µ

F as a passive capacitor

for each V

SS

/V

CC

 pair. Mount the passive capacitors close to the SH7709S power supply pins, and

use components with a frequency characteristic suitable for the chip’s operating frequency, as well
as a suitable capacitance value.

Digital system V

SS

/V

CC

 pairs: 19-21, 27-29, 33-35, 45-47, 57-59, 69-71, 79-81, 83-85, 95-97, 109-

111, 132-134, 153-154, 161-163, 173-175, 181-183, 205-208

On-chip oscillator V

SS

/V

CC

 pairs: 3-6, 145-147, 148-150

Note:

The pin numbers above apply to LQFP and HQFP packages.

When Using a PLL Oscillator Circuit: Keep the wiring from the PLL V

CC

 and V

SS

 connection

pattern to the power supply pins short, and make the pattern width large, to minimize the
inductance component. Ground the oscillation stabilization capacitors C1 and C2 to V

SS

 (PLL1)

and V

SS

 (PLL2), respectively. Place C1 and C2 close to the CAP1 and CAP2 pins and do not

locate a wiring pattern in the vicinity. In clock mode 7, connect the EXTAL pin to V

CC

 or V

SS

 and

leave the XTAL pin open.