s908gz60cfa Freescale Semiconductor, Inc, s908gz60cfa Datasheet - Page 323

• Manufacturer Part Number: s908gz60cfa
• Description: M68hc08 Microcontrollers
• Manufacturer: Freescale Semiconductor, Inc

21.9.3 CGM Acquisition/Lock Time Information
Freescale Semiconductor
Acquisition mode entry frequency tolerance
Tracking mode entry frequency tolerance
LOCK entry frequency tolerance
LOCK exit frequency tolerance
Reference cycles per acquisition mode period
Reference cycles per tracking mode period
Automatic mode time to stable
Automatic stable to lock time
Automatic lock time (t
PLL jitter, deviation of average bus frequency
1. Deviation between VCO frequency and desired frequency to enter PLL acquisition mode.
2. Deviation between VCO frequency and desired frequency to enter PLL tracking mode (stable).
3. Deviation between VCO frequency and desired frequency to enter locked mode.
4. Deviation between VCO frequency and desired frequency to exit locked mode.
5. Acquisition time is an integer multiple of reference cycles divided by reference clock.
6. Stable to lock time is an integer multiple of reference cycles divided by reference clock.
7. Maximum lock time depends on CGMXFC filter components, power supply filtering, and reference clock stability. PLL may
over 2 ms period
not lock if improper components or poor filtering and layout are used.
Characteristic
ACQ
MC68HC908GZ60 • MC68HC908GZ48 • MC68HC908GZ32 Data Sheet, Rev. 6
+ t
AL
(4)
)
(7)
(3)
(2)
(1)
Symbol
Δ
t
Δ
n
Δ
Δ
n
t
LOCK
LOCK
ACQ
t
ACQ
ACQ
TRK
UNL
TRK
AL
f
J
n
n
ACQ
TRK
± 0.9
± 3.6
Clock Generation Module (CGM) Characteristics
Min
—
—
—
0
0
/f
0
/f
RCLK
RCLK
See note
See note
Typ
128
—
—
—
—
32
—
5
(5)
(6)
0.025% x
f
RCLK
± 7.2
± 3.6
± 0.9
± 1.8
Max
N/4
25
—
—
—
—
x
Unit
ms
Hz
%
%
%
%
s
s
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