Datasheet

Section 5 Clock Pulse Generator
REJ09B0465-0300 Rev. 3.00 Page 137 of 982
Sep 17, 2010
H8S/20103, H8S/20203, H8S/20223, H8S/20115, H8S/20215, H8S/20235 Group
5.5 Subclock Oscillator
Figure 5.16 shows a block diagram of the subclock oscillator.
2
1
X
X
Figure 5.16 Block Diagram of Subclock Oscillator
5.5.1 Connecting 32.768-kHz Crystal Resonator
Clock pulses can be supplied to the subclock divider by connecting a 32.768-kHz crystal
resonator, as shown in figure 5.17. A damping resistor Rd should be added, if necessary. Since the
resistor values vary depending on the resonator, use values recommended by the resonator
manufacturer.
C
1
C
2
X1
X2
C
1
= C
2
= 15 pF (typ.)
Rd
Figure 5.17 Typical Connection to 32.768-kHz Crystal Resonator
5.5.2 Pin Connection when not Using Subclock
When the subclock is not used, connect pin X1 to VSS and leave pin X2 open, as shown in figure
5.18.
X
1
V
SS
X
2
Open
Figure 5.18 Pin Connection when not Using Subclock