MC68HC908GP20 Datasheet, PDF (128/406 Pages) Freescale Semiconductor, Inc – M68HC08 Microcontrollers

Table 7-2. PRE 1 and PRE0 Programming
PRE1 and PRE0
00
01
10
11
P
Prescaler Multiplier
0
1
1
2
2
4
3
8
VPR1 and 0 — 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.
Table 7-3. VPR1 and VPR0 Programming
VPR1 and VPR0
E
00
0
01
1
10
2
11
3⁽¹⁾
1. Do not program E to a value of 3.
VCO Power-of-Two
Range Multiplier
1
2
4
8
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
Address: $0037
Advance Information
128
MC68HC908GP20 — Rev 2.1
Freescale Semiconductor