mc68hc908jw32 Freescale Semiconductor, Inc, mc68hc908jw32 Datasheet - Page 61

• Manufacturer Part Number: mc68hc908jw32
• Description: M68hc08 Microcontrollers Microcontroller
• Manufacturer: Freescale Semiconductor, Inc

Freescale Semiconductor
3. Calculate N:
4. Calculate and verify the adequacy of the VCO and bus frequencies f
5. Select the VCO’s power-of-two range multiplier E, according to this table:
6. Select a VCO linear range multiplier, L, where f
7. Calculate and verify the adequacy of the VCO programmed center-of-range frequency, f
8. Verify the choice of P, R, N, E, and L by comparing f
center-of-range frequency is the midpoint between the minimum and maximum frequencies
attainable by the PLL.
For proper operation,
operation, f
as possible to f
Exceeding the recommended maximum bus frequency or VCO frequency
can crash the MCU.
VCLK
VCLK.
must be within the application’s tolerance of f
NOTE: Do not program E to a value of 3.
19,660,800 ≤ f
9,830,400 ≤ f
0 < f
MC68HC908JW32 Data Sheet, Rev. 5
Frequency Range
N
VCLK
=
f
VRS
L
f
VCLK
round
VRS
VCLK
=
f
< 9,830,400
VCLK
f
–
BUS
round
f
< 19,660,800
< 39,321,600
VCLK
=
⎛
⎜
⎝
NOTE
R
------------------------------------ -
(
=
=
L
f
×
⎛
⎜
⎝
RCLK
×
2
----------- f
--------------------------
2
f
---------- -
≤
f
VCLK
P
R
E
VCLKDES
2
NOM
f
6
f
--------------------------
N
E
VCLK
×
NOM
)f
(
×
f
NOM
NOM
RCLK
2
= 125kHz
2
VCLK
P
×
⎞
⎟
⎠
2
⎞
⎟
⎠
)
E
to f
VRS
VCLKDES
and f
E
0
1
2
VCLK
, and f
VCLKDES
and f
VRS
Functional Description
BUS
. For proper
must be as close
.
VRS
. The
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