HD6433937 Datasheet, PDF (101/521 Pages) Hitachi Semiconductor – Hardware Manual

4.3 Subclock Generator
1. Connecting a 76.8-kHz/160-kHz crystal oscillator
Clock pulses can be supplied to the subclock divider by connecting a 76.8-kHz/160-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.
DX ₁
DX ₂
C₁
C₂
C₁ = C ₂ = 12.5 pF (typ.)
Figure 4-7 Typical Connection to 76.8-kHz/160-kHz Crystal Oscillator (Subclock)
Figure 4-8 shows the equivalent circuit of the 76.8-kHz/160-kHz crystal oscillator.
DX ₁
C_S
L_S
R_S
DX ₂
C₀
f_W = 76.8 kHz/160 kHz
Figure 4-8 Equivalent Circuit of 76.8-kHz/160-kHz Crystal Oscillator
2. Pin connection when not using subclock
When the subclock is not used, connect pin DX₁ to GND and leave pin DX₂ open, as shown in
figure 4-9.
DX ₁
DX ₂
GND
Open
Figure 4-9 Pin Connection when not Using Subclock
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