mcf51em256 Freescale Semiconductor, Inc, mcf51em256 Datasheet - Page 36

• Manufacturer Part Number: mcf51em256
• Description: Microcontrollers Covers Mcf51em256 Mcf51em128
• Manufacturer: Freescale Semiconductor, Inc

1
2
3
4
Electrical Characteristics
36
Num
10
11
Data in Typical column was characterized at 3.0 V, 25 °C or is typical recommended value.
The resulting bus clock frequency should not exceed the maximum specified bus clock frequency of the device.
This specification applies to any time the FLL reference source or reference divider is changed, trim value changed or changing
from FLL disabled (FBELP, FBILP) to FLL enabled (FEI, FEE, FBE, FBI). 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.
8
9
Table 17. ICS Frequency Specifications (Temperature Range = –40 to 85 °C Ambient) (continued)
C
C
C
C FLL acquisition time
C
Total deviation of trimmed DCO output frequency over voltage
and temperature
Total deviation of trimmed DCO output frequency over fixed
voltage and temperature range of 0
Long term jitter of DCO output clock (averaged over 2 ms
interval)
Figure 13. Deviation of DCO Output from Trimmed Frequency (50.33 MHz, 3.0 V)
4
60
50
40
30
20
10
0
-40
MCF51EM256 Series ColdFire Microcontroller Data Sheet, Rev.3
-30
3
-20
Characteristic
DD
Preliminary—Subject to Change Without Notice
and V
-10
SS
°
0
and variation in crystal oscillator frequency increase the C
C to 70
10
°
C
Temp (C)
25
35
45
55
Symbol
t
Δf
Δf
Acquire
C
65
dco_t
dco_t
Jitter
75
Min
85
—
—
—
—
95
Typical
Freescale Semiconductor
–1.0
±0.5
0.02
0.5
—
Jitter
HR
MR
LR
1
percentage for a
Max
0.2
±2
±1
1
Bus
.
%f
%f
%f
Unit
ms
dco
dco
dco