mc68hc908gr8a Freescale Semiconductor, Inc, mc68hc908gr8a Datasheet - Page 61

• Manufacturer Part Number: mc68hc908gr8a
• Description: M68hc08 Microcontrollers Microcontroller
• Manufacturer: Freescale Semiconductor, Inc

Table 4-1
Freescale Semiconductor
10. Verify the choice of P, R, N, E, and L by comparing f
11. Program the PLL registers accordingly:
operation, f
as possible to f
a. In the PRE bits of the PLL control register (PCTL), program the binary equivalent of P.
b. In the VPR bits of the PLL control register (PCTL), program the binary equivalent of E.
d. In the PLL VCO range select register (PMRS), program the binary coded equivalent of L.
e. In the PLL reference divider select register (PMDS), program the binary coded equivalent
c. In the PLL multiplier select register low (PMSL) and the PLL multiplier select register high
provides numeric examples (numbers are in hexadecimal notation):
(PMSH), program the binary equivalent of N.
of R.
Exceeding the recommended maximum bus frequency or VCO frequency
can crash the MCU.
f
BUS
2.4576
4.9152
7.3728
VCLK
2.0
4.0
8.0
2.0
4.0
8.0
2.0
4.0
8.0
(MHz)
VCLK
must be within the application’s tolerance of f
.
MC68HC908GR8A • MC68HC908GR4A Data Sheet, Rev. 5
f
RCLK
4.9152
4.9152
4.9152
8.0
8.0
8.0
4.0
4.0
4.0
8.0
8.0
8.0
(MHz)
Table 4-1. Numeric Example
P
0
0
0
0
0
0
0
0
0
0
0
0
NOTE
PCTL
E
0
1
2
0
1
2
1
2
2
0
1
2
VCLK
PMSH,L
to f
008
010
020
002
004
008
002
004
006
001
002
004
N
VRS
VCLKDES
and f
PMRS
D0
D0
D0
D0
D0
D0
C0
D0
D0
D0
80
80
L
, and f
VCLKDES
VRS
Functional Description
PMDS
. For proper
R
8
8
8
1
1
1
1
1
1
1
1
1
must be as close
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