mc68hc908ap8cfa Freescale Semiconductor, Inc, mc68hc908ap8cfa Datasheet - Page 75

• Manufacturer Part Number: mc68hc908ap8cfa
• Description: M68hc08 Microcontrollers
• Manufacturer: Freescale Semiconductor, Inc

5.4 RC Oscillator
The RC oscillator circuit is designed for use with an external resistor and a capacitor.
In its typical configuration, the RC oscillator requires two external components, one R and one C.
Component values should have a tolerance of 1% or less, to obtain a clock source with less than 10%
tolerance. The oscillator configuration uses two components:
5.5 X-tal Oscillator
The crystal (x-tal) oscillator circuit is designed for use with an external 32.768kHz crystal to provide an
accurate clock source.
In its typical configuration, the x-tal oscillator is connected in a Pierce oscillator configuration, as shown
in
represent actual circuitry. The oscillator configuration uses five components:
Freescale Semiconductor
Figure
•
•
•
•
•
•
•
C
R
Crystal, X
Fixed capacitor, C
Tuning capacitor, C
Feedback resistor, R
Series resistor, R
EXT
EXT
5-6. This figure shows only the logical representation of the internal components and may not
See
STOP_RCLKEN
1
Chapter 22
MCU
(32.768kHz)
CONFIG2
S
1
for component value requirements.
(optional)
2
B
From SIM
(can also be a fixed capacitor)
SIMOSCEN
MC68HC908AP Family Data Sheet, Rev. 4
Figure 5-5. RC Oscillator
V
REG
EN
To Clock Selection MUX
RCCLK
RC OSCILLATOR
R
OSC1
EXT
C
EXT
BUS CLOCK
From SIM
OSC2
RC Oscillator
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