MCF51AC256BCLKER Freescale Semiconductor, MCF51AC256BCLKER Datasheet - Page 31

• Manufacturer Part Number: MCF51AC256BCLKER
• Description: MCU 32BIT 256K FLASH 80-LQFP
• Manufacturer: Freescale Semiconductor
• Series: MCF51ACr

Specifications of MCF51AC256BCLKER

• Core Processor: Coldfire V1
• Core Size: 32-Bit
• Speed: 50MHz
• Connectivity: I²C, SCI, SPI
• Peripherals: LVD, PWM, WDT
• Number Of I /o: 69
• Program Memory Size: 256KB (256K x 8)
• Program Memory Type: FLASH
• Ram Size: 32K x 8
• Voltage - Supply (vcc/vdd): 2.7 V ~ 5.5 V
• Data Converters: A/D 24x12b
• Oscillator Type: External
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 80-LQFP
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Eeprom Size: -

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5
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8
2.11
This section describes ac timing characteristics for each peripheral system.
Freescale Semiconductor
Num C
18
19
20
21
Data in Typical column was characterized at 5.0 V, 25 C or is typical recommended value.
The resulting bus clock frequency must not exceed the maximum specified bus clock frequency of the device.
This specification applies when 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 when 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
a 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
lock, then the MCG may stay in lock.
Below D
Table 16. MCG Frequency Specifications (continued)(Temperature Range = –40 to 105 C Ambient)
D Lock exit frequency tolerance
D Lock time — FLL
D Lock time — PLL
D
Loss of external clock minimum frequency —
RANGE = 0
lock
unl
AC Characteristics
minimum, the MCG will not exit lock if already in lock. Above D
minimum, the MCG enters lock. Above D
MCF51AC256 ColdFire Microcontroller Data Sheet, Rev.6
Rating
DD
and V
8
SS
and variation in crystal oscillator frequency increase the C
lock
maximum, the MCG will not enter lock. But if the MCG is already in
o
Symbol
t
f
t
pll_lock
loc_low
fll_lock
D
unl
unl
maximum, the MCG is guaranteed to exit lock.
(3/5)  f
4.47
Min
—
—
int
Typical
—
—
—
—
Electrical Characteristics
1
1075(1/
1075(1/
t
t
pll_acquire+
fll_acquire+
5.97
Jitter
Max
—
f
pll_ref)
f
int_t)
percentage for
BUS
.
Unit
kHz
%
s
s
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