HD64F38024HV Datasheet, PDF (133/684 Pages) Renesas Technology Corp – Hardware Manual Renesas 8-Bit Single-Chip Microcomputer H8 Family/H8/300L Super Low Power Series

Section 4 Clock Pulse Generators
4.3 Subclock Generator
Connecting a 32.768 kHz/38.4 kHz Crystal Oscillator
Clock pulses can be supplied to the subclock divider by connecting a 32.768 kHz/38.4 kHz crystal
oscillator, as shown in figure 4.8. Follow the same precautions as noted under 3. notes on board
design for the system clock in section 4.2.
Note that only operation at 32.768 kHz is guaranteed on the H8/38124 Group.
C₁
C¹ = C ² = 15 pF (typ.)
X₁
Frequency Crystal oscillator
Products Name
X₂
38.4 kHz Seiko Instruments Inc. VTC-200
C₂
32.768 kHz Nihon Denpa Kogyo MX73P
C¹ = C ² = 7 pF (typ.)
Frequency Crystal oscillator
Products Name Motion Resistance
32.768 kHz* EPSON TOYOCOM. C-001R
35 kΩ max
Notes: Circuit constants should be detemined in consultation with the
resonator manufacture.
* H8/38124 Group only.
Figure 4.8 Typical Connection to 32.768 kHz/38.4 kHz Crystal Oscillator (Subclock)
Figure 4.9 shows the equivalent circuit of the 32.768 kHz/38.4 kHz crystal oscillator.
C_S
L_S
X₁
R_S
X₂
C₀
C₀ = 1.5 pF typ
R_S = 14 kΩ typ
f _W = 32.768 kHz/38.4 kHz
Figure 4.9 Equivalent Circuit of 32.768 kHz/38.4 kHz Crystal Oscillator
Rev. 8.00 Mar. 09, 2010 Page 111 of 658
REJ09B0042-0800