MC68HC08AZ60CFU MOTOROLA [Motorola, Inc], MC68HC08AZ60CFU Datasheet - Page 120

• Manufacturer Part Number: MC68HC08AZ60CFU
• Description: Advance Information
• Manufacturer: MOTOROLA [Motorola, Inc]

Clock Generator Module (CGM)
MC68HC08AZ60 — Rev 1.0
120
NOTE:
NOTE:
PLLF — PLL Flag Bit
Do not inadvertently clear the PLLF bit. Be aware that any read or
read-modify-write operation on the PLL control register clears the PLLF
bit.
PLLON — PLL On Bit
BCS — Base Clock Select Bit
PLLON and BCS have built-in protection that prevents the base clock
selector circuit from selecting the VCO clock as the source of the base
clock if the PLL is off. Therefore, PLLON cannot be cleared when BCS
is set, and BCS cannot be set when PLLON is clear. If the PLL is off
Freescale Semiconductor, Inc.
This read-only bit is set whenever the LOCK bit toggles. PLLF
generates a CPU interrupt request if the PLLIE bit also is set. PLLF
always reads as logic 0 when the AUTO bit in the PLL bandwidth
control register (PBWC) is clear. Clear the PLLF bit by reading the
PLL control register. Reset clears the PLLF bit.
This read/write bit activates the PLL and enables the VCO clock,
CGMVCLK. PLLON cannot be cleared if the VCO clock is driving the
base clock, CGMOUT (BCS = 1). See
on page 115. Reset sets this bit so that the loop can stabilize as the
MCU is powering up.
This read/write bit selects either the crystal oscillator output,
CGMXCLK, or the VCO clock, CGMVCLK, as the source of the CGM
output, CGMOUT. CGMOUT frequency is one-half the frequency of
the selected clock. BCS cannot be set while the PLLON bit is clear.
After toggling BCS, it may take up to three CGMXCLK and three
CGMVCLK cycles to complete the transition from one source clock to
the other. During the transition, CGMOUT is held in stasis. See
Clock Selector Circuit
clear the BCS bit.
For More Information On This Product,
1 = Change in lock condition
0 = No change in lock condition
1 = PLL on
0 = PLL off
1 = CGMVCLK divided by two drives CGMOUT
0 = CGMXCLK divided by two drives CGMOUT
Clock Generator Module (CGM)
Go to: www.freescale.com
on page 115. Reset and the STOP instruction
Base Clock Selector Circuit
MOTOROLA
Base
16-cgm