h8s-2646 Renesas Electronics Corporation., h8s-2646 Datasheet - Page 765

• Manufacturer Part Number: h8s-2646
• Description: Renesas 16-bit Single-chip Microcomputer H8s Family/h8s/2600 Series
• Manufacturer: Renesas Electronics Corporation.

Handling pins when subclock not required: If no subclock is required, connect the OSC1 pin to
Vss and leave OSC2 open, as shown in figure 21.8.
21.8
To eliminate noise from the subclock input to OSCI, the subclock is sampled using the dividing
clock φ. The sampling frequency is set using the NESEL bit of LPWRCR. For details, see section
22.2.3, Low-Power Control Register (LPWRCR).
No sampling is performed in subactive mode, subsleep mode, or watch mode.
21.9
Since various characteristics related to the crystal resonator are closely linked to the user’s board
design, thorough evaluation is necessary on the user’s part, using the resonator connection
examples shown in this section as a guide. As the resonator circuit ratings will depend on the
floating capacitance of the resonator and the mounting circuit, the ratings should be determined in
consultation with the resonator manufacturer. The design must ensure that a voltage exceeding the
maximum rating is not applied to the oscillator pin.
Subclock Waveform Generation Circuit
Note on Crystal Resonator
Figure 21.8 Pin Handling When Subclock Not Required
OSC2
OSC1
Rev. 5.00 Sep 22, 2005 page 739 of 1136
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Section 21 Clock Pulse Generator
REJ09B0257-0500