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M5253EVBE Users Manual, Rev. 1
3-8
Freescale Semiconductor
3.3
General Purpose I/O Pins
The MCF5253 offers 60-bits of general-purpose I/O of which 6 are dedicated general purpose inputs and
3 are dedicated general purpose outputs. Seven of the GPIO lines are also available as edge sensitive
interrupt inputs plus one dedicated pin is used to generate a WAKEUP interrupt from low power mode.
The functions of all I/O pins are individually programmable, since they are multiplexed with other pin
functions. All general-purpose I/O pins (unless dedicated as either only input or output) can be individually
selected as input or output pins. After reset, all software configurable multi-function GPIO pins default to
general purpose input pins. At the same time, all multifunction pins that are not shared with a GPIO pin
default to high impedance. Internal pullup resistors avoid unknown read values in order to reduce power
consumption. They remain active until the corresponding port direction registers are programmed.
Control registers are provided for each pin to select the function (GPIO or peripheral pin) assigned to each
pin individually. Pins can have from 1 to 4 functions including GPIO.
3.4
Audio Module
The MCF5253 processor’s audio module includes the following features:
•
Support for reception and transmission of digital audio over serial interfaces IIS/EIAJ and digital
interface IEC958
•
3x IIS/EIAJ interfaces
•
2x IEC958 receivers (4x multiplexed inputs)
•
1x IEC958 transmitter - two outputs - one with professional subcoding, one with consumer
subcoding
•
Allows direct transmission of received audio to an audio transmitter without CPU intervention.
•
IEC958 receivers and transmitter support main audio, plus handling of IEC958 C, U and V
sub-channels
•
Frequency measurement block - precise measurement of the incoming sample frequency
3.5
Analog to Digital Converter (ADC) Module
The MCF5253 processor’s ADC module includes the following features:
•
Sigma-Delta based ADC with 12-bit resolution
•
Six dedicated inputs—ADIN0/GPI52, ADIN1/GPI53, ADIN2/GPI54, ADIN3/GPI55,
ADIN4/GPI56, and ADIN5/GPI57
•
Single output—ADOUT/SCLK4/GPIO58, provides the reference voltage which requires an
external integrator (resistor/capacitor circuit)
•
Software interrupt provided when the ADC measurement is complete
3.6
Flash Memory Card/IDE Interface Module
The MCF5253 memory bus allows connection of an IDE hard disk drive or SmartMedia flash card with a
minimum of external hardware. It can interface with both an IDE device and a SmartMedia device