SH7619_09 Datasheet, PDF (253/860 Pages) Renesas Technology Corp – Renesas 32-Bit RISC Microcomputer SuperHTM RISC engine Family / SH7619 Series

Section 8 Clock Pulse Generator (CPG)
8.6 Notes on Board Design
Note on Using an External Crystal Resonator: Place the crystal resonator, capacitors CL1 and
CL2, and feedback resistor R1 as close to the XTAL and EXTAL pins as possible. In addition, to
minimize induction and thus obtain oscillation at the correct frequency, the capacitors to be
attached to the resonator must be grounded to the same ground. Do not bring wiring patterns close
to these components.
Signal lines prohibited
CL1
CL2
Rl
Reference value
CL1 = 10 to 33 pF
CL2 = 10 to 33 pF
Rl = 1MΩ
EXTAL
XTAL
This LSI
Note:
The values for CL1, CL2, and
the damping resistance RI
should be determined after
consultation with the crystal
resonator manufacturer.
Figure 8.2 Note on Using a Crystal Resonator
Notes on Using External Clocks: When external clocks are input from the EXTAL pin, leave the
XTAL pin open. In order to prevent a malfunction due to the reflection noise caused in a signal
line which connected to XTAL pin, cut this signal line as short as possible.
Notes on Bypass Capacitor: A multilayer ceramic capacitor must be inserted for each pair of Vss
and Vcc as a bypass capacitor. The bypass capacitor must be inserted as close as possible to the
power supply pins of the LSI. Note that the capacitance and frequency characteristics of the
bypass capacitor must be appropriate for the operating frequency of the LSI.
• Digital power supply pairs for internal logic
A7-B7, E2-E1, E13-E12, H4-H3, K12-K13, M10-N10
• Power supply pairs for input and output
A1-B1, A9-B9, B15-B14, H14-H15, K1-K2, R7-P7, P13-P14
• Power supply pairs for PLL
N15-N14, R15-P15
• Analog power supply pairs for PHY
N4-(N3, AP3), P4-P5
• No ground available that can be paired with R5 (Vcc3A)
Rev. 6.00 Jul. 15, 2009 Page 213 of 816
REJ09B0237-0600