HD6432621 Hitachi, HD6432621 Datasheet - Page 730

• Manufacturer Part Number: HD6432621
• Description: (HD64F262x Series) 16-Bit Microcomputer
• Manufacturer: Hitachi

(2) Handling pins when subclock not required
If no subclock is required, connect the OSC1 pin to Vcc and leave OSC2 open, as shown in figure
20-10.
20.8
To eliminate noise from the subclock input to OSC1, the subclock is sampled using the dividing
clock ø. The sampling frequency is set using the NESEL bit of LPWRCR. For details, see section
21B.2.3, Low Power Control Register (LPWRCR).
No sampling is performed in sub-active mode, sub-sleep mode, or watch mode.
20.9
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, for both the mask versions and
F-ZTAT versions, 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.
686
Subclock Waveform Shaping Circuit (H8S/2626 Series Only)
Note on Crystal Resonator
Figure 20-10 Pin Handling When Subclock Not Required
OSC2
OSC1
Open
V
CC