MC68HC08JB1 Datasheet, PDF (72/216 Pages) Motorola, Inc – Microcontrollers

7.3 Oscillator External Connections
In its typical configuration, the oscillator requires five external
components. The crystal oscillator is normally connected in a Pierce
oscillator configuration, as shown in Figure 7-1. This figure shows only
the logical representation of the internal components and may not
represent actual circuitry. The oscillator configuration uses five
components:
• Crystal, X₁
• Fixed capacitor, C₁
• Tuning capacitor, C₂ (can also be a fixed capacitor)
• Feedback resistor, R_B
• Series resistor, R_S (optional)
FROM
SIM
TO USB
TO SIM
TO SIM
SIMOSCEN
MCU
OSC1
R_B
CLOCK OSCXCLK
DOUBLER
OSC2
÷2 ^OSCOUT
R_S*
X1
C1
C2
* R_S can be 0 (shorted) when used with higher-frequency crystals. Refer to manufacturer’s data.
Figure 7-1. Oscillator External Connections
Technical Data
72
MC68HC08JB1 — Rev. 2.1
Freescale Semiconductor