Clock Generator Module (CGMC)
CGMC Registers
MC68HC908GP32
•
MC68HC08GP32
—
Rev. 6
Technical Data
MOTOROLA
Clock Generator Module (CGMC)
125
VPR1 and VPR0 — VCO Power-of-Two Range Select Bits
These read/write bits control the VCO’s hardware power-of-two range
multiplier E that, in conjunction with L (See
7.4.3 PLL Circuits
,
7.4.6
Programming the PLL
, and
7.6.5 PLL VCO Range Select
Register
.) controls the hardware center-of-range frequency, f
VRS
.
VPR1:VPR0 cannot be written when the PLLON bit is set. Reset
clears these bits.
7.6.2 PLL
Bandwidth Control Register
The PLL bandwidth control register (PBWC):
•
Selects automatic or manual (software-controlled) bandwidth
control mode
•
Indicates when the PLL is locked
•
In automatic bandwidth control mode, indicates when the PLL is in
acquisition or tracking mode
•
In manual operation, forces the PLL into acquisition or tracking
mode
Table 7-2. PRE1 and PRE0 Programming
PRE1 and PRE0
P
Prescaler Multiplier
00
0
1
01
1
2
10
2
4
11
3
8
Table 7-3. VPR1 and VPR0 Programming
VPR1 and VPR0
E
VCO Power-of-Two
Range Multiplier
00
0
1
01
1
2
10
2
4
11
3
(1)
1. Do not program E to a value of 3.
8
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Freescale Semiconductor, Inc.
For More Information On This Product,
Go to: www.freescale.com
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