HD6473887 Datasheet, PDF (109/523 Pages) Renesas Technology Corp – Hitachi Single-Chip Microcomputer

4.3 Subclock Generator
1. 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 4-7. Follow the same precautions as noted under 3. notes on board
design for the system clock in 4.2.
C₁
X₁
X₂
C₂
C₁ = C ₂ = 15 pF (typ.)
Figure 4-7 Typical Connection to 32.768-kHz/38.4 kHz Crystal Oscillator (Subclock)
Figure 4-8 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/38.4kHz
Figure 4-8 Equivalent Circuit of 32.768-kHz/38.4 kHz Crystal Oscillator
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