MC68HC708XL36 FREESCALE [Freescale Semiconductor, Inc], MC68HC708XL36 Datasheet - Page 103

• Manufacturer Part Number: MC68HC708XL36
• Description: HCMOS Microcontroller Unit
• Manufacturer: FREESCALE [Freescale Semiconductor, Inc]

21-cgm1m_a
MOTOROLA
NOTE:
NOTE:
The multiplier select bits have built-in protection that prevents them from
being written when the PLL is on (PLLON = 1).
VRS[7:4] — VCO Range Select Bits
The VCO range select bits have built-in protection that prevents them
from being written when the PLL is on (PLLON = 1) and prevents
selection of the VCO clock as the source of the base clock (BCS = 1) if
the VCO range select bits are all clear.
The VCO range select bits must be programmed correctly. Incorrect
programming can result in failure of the PLL to achieve lock.
These read/write bits control the hardware center-of-range linear
multiplier L, which controls the hardware center-of-range frequency
f
and
when the PLLON bit in the PLL control register (PCTL) is set. (See
Special Programming Exceptions
VCO range select bits disables the PLL and clears the BCS bit in the
PCTL. (See
Programming Exceptions
initializes the bits to $6 to give a default range multiply value of 6.
Freescale Semiconductor, Inc.
vrs
For More Information On This Product,
. (See
PLL Control Register
Circuits
Go to: www.freescale.com
Base Clock Selector Circuit
on page 88,
CGM
on page 98.) VRS[7:4] cannot be written
on page 93 for more information.) Reset
Programming the PLL
on page 93.) A value of $0 in the
on page 94 and
MC68HC708XL36
CGM Registers
on page 92,
Special
CGM
103