HD6417660 RENESAS [Renesas Technology Corp], HD6417660 Datasheet - Page 383

• Manufacturer Part Number: HD6417660
• Description: Renesas 32-Bit RISC Microcomputer
• Manufacturer: RENESAS [Renesas Technology Corp]

Notes on Using a PLL Oscillator Circuit: Circuitry as shown in figure 11.3 is recommended
around the PLL. In the Vcc and Vss connection pattern for the PLL, signal lines from the board
power supply pins must be as short as possible and pattern width must be as wide as possible to
reduce inductive interference.
In clock operating mode 7, the EXTAL pin is pulled up and the XTAL pin is left open.
Since the analog power supply pins of the PLL are sensitive to the noise, the system may
malfunction due to inductive interference at the power supply pins. To prevent such malfunction,
the analog power supply pin Vcc and digital power supply pin Vcc should not supply the same
resources on the board if at all possible.
Please read “Vcc for PLL” above-mentioned as “VDD for PLL” when you do not select a built-in
regulator (i.e. VDD external power supply is used).
Figure 11.3 Note on Using a PLL Oscillator Circuit
Vcc(PLL)
Vss(PLL)
Vcc
Vss
Power
supply
Rev. 1.00, 02/04, page 345 of 804