r8a77850anbg Renesas Electronics Corporation., r8a77850anbg Datasheet - Page 786

• Manufacturer Part Number: r8a77850anbg
• Description: Renesas 32-bit Risc Microcomputer Superh? Risc Engine Family
• Manufacturer: Renesas Electronics Corporation.

15. Clock Pulse Generator (CPG)
15.7
1. Note on Using a Crystal Resonator
2. Note on Inputting the External Clock from the EXTAL Pin
3. Note on Using a PLL Oscillator Circuit
Rev.1.00 Jan. 10, 2008 Page 756 of 1658
REJ09B0261-0100
Place the crystal resonator and capacitors close to the EXTAL and XTAL pins as much as
possible. No other signal lines should cross the signal line of these pins. Induction may prevent
correct oscillation.
Do not connect anything to the XTAL pin.
Place VDDQ-PLL1, VDDQ-PLL2, VSSQ-PLL1, and VSSQ-PLL2 away from other VDDs
and VSSs on the power supply of the board. Insert resistors RCB, and bypass capacitors, CPB
and CB, as noise filters near the pins.
Crossing of signal lines
is prohibited
Note:
Notes on Designing Board
The values of CL1, CL2, and the dumping resistance should be determined through
evaluation and consultation with the manufacturer of the crystal resonator to be used.
Figure 15.4 Note on Using a Crystal Resonator
CL1
EXTAL
SH7785
XTAL
CL2
R
Recommended values
CL1 = CL2 = 0 to 33 pF
R = 0 Ω