MC68HC908AB32 MOTOROLA [Motorola, Inc], MC68HC908AB32 Datasheet - Page 143

• Manufacturer Part Number: MC68HC908AB32
• Description: HCMOS Microcontroller Unit
• Manufacturer: MOTOROLA [Motorola, Inc]

9.5.6 Crystal Output Frequency Signal (CGMXCLK)
9.5.7 CGM Base Clock Output (CGMOUT)
9.5.8 CGM CPU Interrupt (CGMINT)
9.6 CGM Registers
MC68HC908AB32
MOTOROLA
—
Rev. 1.0
CGMXCLK is the crystal oscillator output signal. It runs at the full speed
of the crystal (f
circuit.
and OSC2 and may not represent the actual circuitry. The duty cycle of
CGMXCLK is unknown and may depend on the crystal and other
external factors. Also, the frequency and amplitude of CGMXCLK can be
unstable at start-up.
CGMOUT is the clock output of the CGM. This signal goes to the SIM,
which generates the MCU clocks. CGMOUT is a 50% duty cycle clock
running at twice the bus frequency. CGMOUT is software programmable
to be either the oscillator output (CGMXCLK) divided by two or the VCO
clock (CGMVCLK) divided by two.
CGMINT is the interrupt signal generated by the PLL lock detector.
The following registers control and monitor operation of the CGM:
Figure 9-4
•
•
•
Freescale Semiconductor, Inc.
For More Information On This Product,
PLL control register (PCTL). (See
(PCTL))
PLL bandwidth control register (PBWC). (See
Bandwidth Control Register
PLL programming register (PPG). (See
Register
Figure 9-3
Clock Generator Module (CGM)
is a summary of the CGM registers.
Go to: www.freescale.com
XCLK
(PPG))
shows only the logical relation of CGMXCLK to OSC1
) and is generated directly from the crystal oscillator
(PBWC))
9.6.1 PLL Control Register
Clock Generator Module (CGM)
9.6.3 PLL Programming
9.6.2 PLL
CGM Registers
Technical Data
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