MCF51EM256CLL Freescale Semiconductor, MCF51EM256CLL Datasheet - Page 53

• Manufacturer Part Number: MCF51EM256CLL
• Description: IC MCU 32BIT 256KB FLASH 100LQFP
• Manufacturer: Freescale Semiconductor
• Series: MCF51EMr

Specifications of MCF51EM256CLL

• Core Processor: Coldfire V1
• Core Size: 32-Bit
• Speed: 50MHz
• Connectivity: I²C, SCI, SPI
• Peripherals: LCD, LVD, PWM, WDT
• Number Of I /o: 63
• Program Memory Size: 256KB (256K x 8)
• Program Memory Type: FLASH
• Ram Size: 16K x 8
• Voltage - Supply (vcc/vdd): 1.8 V ~ 3.6 V
• Data Converters: A/D 16x12b
• Oscillator Type: External
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 100-LQFP
• Processor Series: MCF51EM
• Core: ColdFire V1
• Data Bus Width: 32 bit
• Data Ram Size: 16 KB
• Interface Type: RS-232, LIN
• Maximum Clock Frequency: 50 MHz
• Number Of Timers: 3
• Operating Supply Voltage: 1.8 V to 3.6 V
• Maximum Operating Temperature: + 85 C
• Mounting Style: SMD/SMT
• 3rd Party Development Tools: JLINK-CF-BDM26, EWCF
• Development Tools By Supplier: DEMOEM
• Minimum Operating Temperature: - 40 C
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Eeprom Size: -
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant

2.2.2
V
supplies power to all I/O buffer circuitry and to an internal voltage regulator; V
of IRTC and OSC1. The internal voltage regulator provides regulated lower-voltage source to the CPU and
other internal circuitry of the microcontroller.
Typically, application systems have two separate capacitor values across the power pins. In this case, there
must be a bulk electrolytic capacitor, such as a 10 μF tantalum capacitor, to provide bulk charge storage
for the overall system and a 0.1 μF ceramic bypass capacitor located as close to the microcontroller power
pins as practical to suppress high-frequency noise. Each MCF51EM256 series V
ceramic bypass capacitor for best noise suppression.
V
power to the ADC module. A 0.1 μF ceramic bypass capacitor should be located as close to the
microcontroller power pins as practical to suppress high-frequency noise. V
module as well.
2.2.3
Immediately after reset, the microcontroller uses an internally generated clock provided by the internal
clock source (ICS) module.
The oscillator (XOSC) in this microcontroller is a Pierce oscillator that can accommodate a crystal or
ceramic resonator. Optionally, an external clock source can be connected to the EXTAL input pin.
Refer to
such as carbon composition resistors. Wire-wound resistors, and some metal film resistors, have too much
inductance. C1 and C2 normally must be high-quality ceramic capacitors that are specifically designed for
high-frequency applications.
R
is not generally critical. Typical systems use 1 MΩ to 10 MΩ. Higher values are sensitive to humidity and
lower values reduce gain and (in extreme cases) could prevent startup.
C1 and C2 are typically in the 5 pF to 25 pF range and are chosen to match the requirements of a specific
crystal or resonator. Be sure to take into account printed circuit board (PCB) capacitance and
microcontroller pin capacitance when selecting C1 and C2. The crystal manufacturer typically specifies a
load capacitance which is the series combination of C1 and C2 (which are usually the same size). As a
first-order approximation, use 10 pF as an estimate of combined pin and PCB capacitance for each
oscillator pin (EXTAL and XTAL).
Freescale Semiconductor
F
DD
DDA
is used to provide a bias path to keep the EXTAL input in its linear range during crystal startup; its value
, V
and V
BAT
Figure 2-3
and V
Power
Oscillator
SSA
MCF51EM256 Series ColdFire Integrated Microcontroller Reference Manual, Rev. 8
are the analog power supply pins for the microcontroller. This voltage source supplies
SS1,
for the following discussion. R
V
SS2
are the primary power supply pins for the microcontroller. V
S
(when used) and R
F
must be low-inductance resistors
DDA
BAT
DD
supplies PRACMP
pin must have a 0.1 μF
only supply the power
DD
Pins and Connections
, V
SS1
and V
2-21
SS2