MC68HC908AB32 MOTOROLA [Motorola, Inc], MC68HC908AB32 Datasheet - Page 149

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

MC68HC908AB32
MOTOROLA
NOTE:
NOTE:
—
Rev. 1.0
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 may 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
9.6.1 PLL Control Register
when the PLLON bit in the PLL control register (PCTL) is set. (See
9.4.2.5 Special Programming
VCO range select bits disables the PLL and clears the BCS bit in the
PCTL. (See
Programming Exceptions
the bits to $6 to give a default range multiply value of 6.
Freescale Semiconductor, Inc.
VRS
For More Information On This Product,
MUL7:MUL6:MUL5:MUL4
. (See
Table 9-1. VCO Frequency Multiplier (N) Selection
Clock Generator Module (CGM)
Go to: www.freescale.com
9.4.2.1 PLL
0000
0001
0010
0011
1101
1110
1111
9.4.3 Base Clock Selector Circuit
Circuits,
for more information). Reset initializes
(PCTL)). VRS[7:4] cannot be written
Exceptions). A value of $0 in the
9.4.2.4 Programming the
VCO Frequency Multiplier (N)
Clock Generator Module (CGM)
and
13
14
15
1
1
2
3
9.4.2.5 Special
CGM Registers
Technical Data
PLL, and
149