MC68HC11E0CFN2 Freescale Semiconductor, MC68HC11E0CFN2 Datasheet - Page 63

• Manufacturer Part Number: MC68HC11E0CFN2
• Description: IC MCU 2MHZ 52-PLCC
• Manufacturer: Freescale Semiconductor
• Series: HC11r

Specifications of MC68HC11E0CFN2

• Core Processor: HC11
• Core Size: 8-Bit
• Speed: 2MHz
• Connectivity: SCI, SPI
• Peripherals: POR, WDT
• Number Of I /o: 38
• Program Memory Type: ROMless
• Ram Size: 512 x 8
• Voltage - Supply (vcc/vdd): 4.5 V ~ 5.5 V
• Data Converters: A/D 8x8b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 52-PLCC
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Eeprom Size: -
• Program Memory Size: -

3.1 Introduction
3.2 Overview
3.2.1 Multiplexer
M68HC11E Family — Rev. 5
MOTOROLA
Data Sheet — M68HC11E Family
The analog-to-digital (A/D) system, a successive approximation converter, uses an
all-capacitive charge redistribution technique to convert analog signals to digital
values.
The A/D system is an 8-channel, 8-bit, multiplexed-input converter. The converter
does not require external sample and hold circuits because of the type of charge
redistribution technique used. A/D converter timing can be synchronized to the
system E clock or to an internal resistor capacitor (RC) oscillator.
The A/D converter system consists of four functional blocks: multiplexer, analog
converter, digital control, and result storage. Refer to
The multiplexer selects one of 16 inputs for conversion. Input selection is controlled
by the value of bits CD:CA in the ADCTL register. The eight port E pins are
fixed-direction analog inputs to the multiplexer, and additional internal analog
signal lines are routed to it.
Port E pins also can be used as digital inputs. Digital reads of port E pins are not
recommended during the sample portion of an A/D conversion cycle, when the
gate signal to the N-channel input gate is on. Because no P-channel devices are
directly connected to either input pins or reference voltage pins, voltages above
V
to maximum ratings. Refer to
input pin.
DD
do not cause a latchup problem, although current should be limited according
Freescale Semiconductor, Inc.
For More Information On This Product,
Analog-to-Digital (A/D) Converter
Go to: www.freescale.com
Section 3. Analog-to-Digital (A/D) Converter
Figure
3-2, which is a functional diagram of an
Figure
3-1.
Data Sheet
63