mc68hc908as60 Freescale Semiconductor, Inc, mc68hc908as60 Datasheet - Page 164

• Manufacturer Part Number: mc68hc908as60
• Description: Mc68hc908as60 Microcontroller
• Manufacturer: Freescale Semiconductor, Inc

Clock Generator Module (CGM)
Technical Data
NOTE:
For proper operation,
Exceeding the recommended maximum bus frequency or VCO
frequency can crash the MCU.
5. Calculate the bus frequency, f
6. If the calculated f
7. Using the value 4.9152 MHz for f
8. Calculate the VCO center-of-range frequency, f
9. Program the PLL registers accordingly:
Freescale Semiconductor, Inc.
For More Information On This Product,
f
application, select another f
range multiplier, L. The linear range multiplier controls the
frequency range of the PLL.
center-of-range frequency is the midpoint between the minimum
and maximum frequencies attainable by the PLL.
BUSDES
a. In the upper four bits of the PLL programming register (PPG),
b. In the lower four bits of the PLL programming register (PPG),
Clock Generator Module (CGM)
program the binary equivalent of N.
program the binary equivalent of L.
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Example: f
.
Example:
Example:
f
VRS
BUS
f
VRS
BUS
L
–
=
is not within the tolerance limits of the
f
f
= 7
VRS
f
BUS
=
VCLK
round
L
f
-------------
=
VCLK
=
= L
4
BUSDES
4.9152 MHz = 34.4 MHz
------------------------------- -
4.9152 MHz
32 MHz
------------------- -
BUS
32 MHz
f
--------------- -
f
------------ -
f
NOM
VCLK
NOM
4
2
f
NOM
NOM
, and compare f
.
or another f
, calculate the VCO linear
=
MC68HC908AS60 — Rev. 1.0
8 MHz
=
7
RCLK
VRS
BUS
. The
.
with