mc68hc908jb16 Freescale Semiconductor, Inc, mc68hc908jb16 Datasheet - Page 250

• Manufacturer Part Number: mc68hc908jb16
• Description: M68hc08 Microcontrollers Microcontroller
• Manufacturer: Freescale Semiconductor, Inc

Clock Generator Module (CGM)
13.3.1 Reference Frequency Source (OSCXCLK)
13.3.2 Voltage Controlled Oscillator
Technical Data
250
OSCXCLK
REFERENCE
DIVIDER
RDS[9:0]
R
CGMRCLK
The OSCXCLK signal is a buffered output of the crystal oscillator circuit
and runs at a rate equal to the crystal frequency. OSCXCLK is used as
the reference frequency source for both CGM modules.
The VCO clock frequency (CGMVCLK) is generated internally and it is
proportional to the controlled voltage setting by the phase detector
output. The VCO operating range is programmable for a wide range of
frequencies and for maximum immunity to external noise. The
CGMVCLK signal is also the CGM output signal, CGMOUT.
Figure 13-2. CGM Block Diagram
Clock Generator Module (CGM)
DETECTOR
DETECTOR
CGMFCLK
PHD_[7:0]
PHASE
LOCK
LOCK
V
DDA
VDS[11:0]
CGMXFC
DIVIDER
FILTER
LOOP
VCO
N
PLL ANALOG
V
SSA
PLLON
CONTROLLED
OSCILLATOR
CGMVCLK
VOLTAGE
V
MC68HC908JB16
REGA
Freescale Semiconductor
VCO_[7:0]
—
CGMOUT
Rev. 1.1