mcf51jm128 Freescale Semiconductor, Inc, mcf51jm128 Datasheet - Page 31

• Manufacturer Part Number: mcf51jm128
• Description: Mcf51jm128 Coldfire Microcontroller Flexis 32-bit V1 Coldfire? Usb Microcontroller
• Manufacturer: Freescale Semiconductor, Inc

1
2
3
4
5
6
7
2.11
This section describes ac timing characteristics for each peripheral system.
Freescale Semiconductor
Num C
13
14
17
18
19
20
21
22
TRIM register at default value (0x80) and FTRIM control bit at default value (0x0).
This specification applies to any time the FLL reference source or reference divider is changed, trim value changed or changing
from FLL disabled (BLPE, BLPI) to FLL enabled (FEI, FEE, FBE, FBI). If a crystal/resonator is being used as the reference,
this specification assumes it is already running.
This specification applies to any time the PLL VCO divider or reference divider is changed, or changing from PLL disabled
(BLPE, BLPI) to PLL enabled (PBE, PEE). If a crystal/resonator is being used as the reference, this specification assumes it is
already running.
Jitter is the average deviation from the programmed frequency measured over the specified interval at maximum f
Measurements are made with the device powered by filtered supplies and clocked by a stable external clock signal. Noise
injected into the FLL circuitry via V
given interval.
625 ns represents 5 time quanta for CAN applications, under worst case conditions of 8 MHz CAN bus clock, 1 Mbps CAN bus
speed, and 8 time quanta per bit for bit time settings. 5 time quanta is the minimum time between a synchronization edge and
the sample point of a bit using 8 time quanta per bit.
Below D
MCG is already in lock, then the MCG may stay in lock.
Below D
Table 16. MCG Frequency Specifications (continued)(Temperature Range = –40 to 125°C Ambient)
C
D VCO operating frequency
D Lock entry frequency tolerance
D Lock exit frequency tolerance
D Lock time - FLL
D Lock time - PLL
D
T
Long term Jitter of DCO output clock
(averaged over 2ms interval)
Jitter of PLL output clock measured
over 625 ns
Loss of external clock minimum
frequency - RANGE = 0
lock
unl
AC Characteristics
minimum, the MCG does not exit lock if already in lock. Above D
minimum, the MCG is guaranteed to enter lock. Above D
5
Rating
DD
MCF51JM128 ColdFire Microcontroller, Rev. 0
and V
4
7
6
SS
and variation in crystal oscillator frequency increase the C
f
pll_jitter_625ns
Symbol
f
t
t
C
pll_lock
loc_low
D
fll_lock
D
f
Jitter
vco
lock
unl
lock
maximum, the MCG does not enter lock. But if the
(3/5) x f
± 1.49
± 4.47
unl
Min
7.0
—
—
—
—
maximum, the MCG is guaranteed to exit lock.
int
Preliminary Electrical Characteristics
Typical
0.566
0.02
—
—
—
—
—
—
5
1075(1/
t
1075(1/
t
pll_acquire+
fll_acquire+
± 2.98
± 5.97
Max
55.0
0.2
Jitter
—
ef)
—
)
f
f
int_t
pll_r
percentage for a
BUS
%f
MHz
Unit
%f
kHz
%
%
.
s
s
dco
pll
31