HD6417705 Datasheet, PDF (329/739 Pages) Renesas Technology Corp – Renesas 32-Bit RISC Microcomputer SuperH RISC engine Family/SH7700 Series

9.6 Usage Notes
When Using an External Crystal Resonator: Place the crystal resonator, capacitors CL1 and
CL2, and damping resistance R as close as possible 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.
Avoid crossing
signal lines
CL1
CL2
EXTAL
R
XTAL
This LSI
Note: The values for CL1, CL2, and damping resistance
should be determined after consultation with the
crystal resonator manufacturer.
Figure 9.2 Points for Attention when Using Crystal Resonator
Decoupling Capacitors: As far as possible, insert a laminated ceramic capacitor of 0.1 to 1 µF as
a passive capacitor for each V_SS/V_SSQ and V_CC/V_CCQ pair. Mount the passive capacitors as close
as possible to the chip’s 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_SSQ and V_CC/V_CCQ pairs: 2-5, 17-19, 26-28, 32-34, 44-46, 57-59, 69-71, 78-
80, 87-89, 111-113, 130-132, 133-138, 159-161, 178-180, 182-184, 199-204
On-chip oscillator V_SS/V_SSQ and V_CC/V_CCQ pairs: 6-9, 149-150, 151-152, 205-208
When Using a PLL Oscillator Circuit: Keep the wiring from the PLL V_CC and PLL V_SS
connection pattern to the power supply pins short, and make the pattern width wide, to minimize
the inductance value.
In clock mode 7, connect the EXTAL pin to V_CCQ (3.3-V power) with pull-up resistor, and leave
the XTAL pin open.
Rev. 2.00, 09/03, page 283 of 690