Freescale Semiconductor Eval, Demo and Development Board for MCF51MM256 TWR-MCF51MM TWR-MCF51MM Data Sheet
Product codes
TWR-MCF51MM
Electrical Characteristics
Freescale Semiconductor
37
3.10 MCG and External Oscillator (XOSC) Characteristics
Table 18. MCG (Temperature Range = –40 to 105
°
C Ambient)
#
Rating
Symbol
Min
Typical
Max
Unit
C
1 Internal reference startup time
t
irefst
—
55
100
s
D
2
Average internal reference
frequency
frequency
factory trimmed at
VDD=3.0 V and
temp=25C
VDD=3.0 V and
temp=25C
f
int_ft
—
31.25
—
kHz
C
user trimmed
31.25
—
39.0625
C
3
DCO output frequency range —
trimmed
trimmed
Low range
(DRS=00)
(DRS=00)
f
dco_t
16
—
20
MHz
C
Mid range
(DRS=01)
(DRS=01)
32
—
40
C
High range
1
(DRS=10)
1
This should not exceed the maximum CPU frequency for this device which is 50.33 MHz.
40
—
60
C
4
Resolution of trimmed DCO
output frequency at fixed voltage
and temperature
output frequency at fixed voltage
and temperature
with FTRIM
f
dco_res_t
—
0.1
0.2
%f
dco
C
without FTRIM
—
0.2
0.4
C
5
Total deviation of trimmed DCO
output frequency over voltage and
temperature
output frequency over voltage and
temperature
over voltage and
temperature
temperature
f
dco_t
—
1.0
2
%f
dco
P
over fixed voltage
and temp range
of 0 – 70 C
and temp range
of 0 – 70 C
—
0.5
1
C
6
Acquisition time
FLL
2
t
fll_acquire
—
—
1
ms
C
PLL
3
t
pll_acquire
—
—
1
D
7
Long term Jitter of DCO output clock (averaged over
2mS interval)
2mS interval)
4
C
Jitter
—
0.02
0.2
%f
dco
C
8 VCO operating frequency
f
vco
7.0
—
55.0
MHz
D
9 PLL reference frequency range
f
pll_ref
1.0
—
2.0
MHz
D
10
Jitter of PLL output clock
measured over 625ns
measured over 625ns
5
Long term
f
pll_jitter_625
ns
—
0.566
4
—
%f
pll
D
11 Lock frequency tolerance
Entry
6
D
lock
1.49
—
2.98
%
D
Exit
7
D
unl
4.47
—
5.97
D
12 Lock time
FLL
t
fll_lock
—
—
t
fll_acquire+
1075(1/
f
int_t)
s
D
PLL
t
pll_lock
—
—
t
pll_acquire+
1075(1/
f
pll_re
f)
D
13
Loss of external clock minimum frequency - RANGE =
0
0
f
loc_low
(3/5) x
f
int_t
—
—
kHz
D
14
Loss of external clock minimum frequency - RANGE =
1
1
f
loc_high
(16/5) x
f
int_t
—
—
kHz
D
MCF51MM256/128, Rev. 5