Datasheet

Section 23A Clock Pulse Generator
(H8S/2633, H8S/2632, H8S/2631, H8S/2633F)
Page 1002 of 1434 R01UH0166EJ0600 Rev. 6.00
Mar 02, 2011
H8S/2633 Group, H8S/2633 F-ZTAT
TM
,
H8S/2633R F-ZTAT
TM
, H8S/2695
23A.6 Bus Master Clock Selection Circuit
The bus master clock selection circuit selects the system clock (φ) or one of the medium-speed
clocks (φ/2, φ/4, φ/8, φ/16, and φ/32) to be supplied to the bus master, according to the settings of
the SCK2 to SCK0 bits in SCKCR.
23A.7 Subclock Oscillator
(1) Connecting 32.768kHz Quartz Resonator
To supply a clock to the subclock oscillator, connect a 32.768kHz quartz resonator, as shown in
figure 23A.8. See section 23A.3.1, Notes on Board Design for notes on connecting crystal
resonators.
OSC1
OSC2
C
1
C
2
C
1
= C
2
= 15 pF (typ)
Figure 23A.8 Example Connection of 32.768kHz Crystal Resonator
Figure 23A.9 shows the equivalence circuit for a 32.768kHz resonator.
OSC1 OSC2
C
S
L
S
R
S
C
0
C
0
= 1.5pF (typ.)
R
S
= 14kΩ (typ.)
f
W
= 32.768 kHz
Type No.: MX38T (Nihon Dempa Kogyo)
Figure 23A.9 Equivalence Circuit for 32.768kHz Resonator