mc68hc908qf4 Freescale Semiconductor, Inc, mc68hc908qf4 Datasheet - Page 96

• Manufacturer Part Number: mc68hc908qf4
• Description: M68hc08 Microcontrollers Microcontroller
• Manufacturer: Freescale Semiconductor, Inc

Oscillator Module (OSC)
11.4.2 Crystal Amplifier Output Pin (OSC2/PTA4/BUSCLKX4)
11.4.3 Oscillator Enable Signal (SIMOSCEN)
11.4.4 XTAL Oscillator Clock (XTALCLK)
11.4.5 RC Oscillator Clock (RCCLK)
Data Sheet
96
For the internal oscillator configuration, the OSC1 pin can assume other functions
according to
For the XTAL oscillator device, the OSC2 pin is the crystal oscillator inverting
amplifier output.
For the external clock option, the OSC2 pin is dedicated to the PTA4 I/O function.
The OSC2EN bit has no effect.
For the internal oscillator or RC oscillator options, the OSC2 pin can assume other
functions according to
clock (BUSCLKX4).
The SIMOSCEN signal comes from the system integration module (SIM) and
enables/disables either the XTAL oscillator circuit, the RC oscillator, or the internal
oscillator.
XTALCLK is the XTAL oscillator output signal. It runs at the full speed of the crystal
(f
only the logical relation of XTALCLK to OSC1 and OSC2 and may not represent
the actual circuitry. The duty cycle of XTALCLK is unknown and may depend on
the crystal and other external factors. Also, the frequency and amplitude of
XTALCLK can be unstable at start up.
RCCLK is the RC oscillator output signal. Its frequency is directly proportional to
the time constant of external R and internal C.
relation of RCCLK to OSC1 and may not represent the actual circuitry.
XCLK
) and comes directly from the crystal oscillator circuit.
Freescale Semiconductor, Inc.
For More Information On This Product,
Internal oscillator
XTAL oscillator
External clock
Table 1-1. Pin
RC oscillator
Option
Go to: www.freescale.com
or
Oscillator Module (OSC)
Table 1-1. Pin
Table 11-1. OSC2 Pin Function
Functions.
Controlled by OSC2EN bit in PTAPUE register
OSC2EN = 1: BUSCLKX4 output
Functions, or the output of the oscillator
OSC2EN = 0: PTA4 I/O
OSC2 Pin Function
Inverting OSC1
PTA4 I/O
Figure 11-3
MC68HC908QF4 — Rev. 1.0
shows only the logical
Figure 11-2
MOTOROLA
shows