HD6473887 Datasheet, PDF (106/523 Pages) Renesas Technology Corp – Hitachi Single-Chip Microcomputer

4.2 System Clock Generator
Clock pulses can be supplied to the system clock divider either by connecting a crystal or ceramic
oscillator, or by providing external clock input.
1. Connecting a crystal oscillator
Figure 4-2 shows a typical method of connecting a crystal oscillator.
OSC ₁
OSC ₂
C₁
R_f
C₂
R _f = 1 MΩ ±20%
Oscillation
frequency
1.0 MHz
4.19 MHz
Manufacturer
Nihon Denpa Kogyo
Nihon Denpa Kogyo
Recommended value
for C₁ and C₂
27 pF ±10%
12 pF ±20%
Figure 4-2 Typical Connection to Crystal Oscillator
Figure 4-3 shows the equivalent circuit of a crystal oscillator. An oscillator having the
characteristics given in table 4-1 should be used.
OSC₁
C_S
L_S
R_S
OSC₂
C₀
Figure 4-3 Equivalent Circuit of Crystal Oscillator
Table 4-1 Crystal Oscillator Parameters
Frequency
R_S (max)
C₀ (max)
1 MHz
40
3.5 pF
4.193 MHz
100
16 pF
89