SCF5250 Datasheet, PDF (17/48 Pages) Motorola, Inc – SCF5250 Integrated ColdFire Microprocessor

4.12 Digital Audio Interface Signals
Signal Descriptions
Table 9. Digital Audio Interface Signals
Serial Module Signal
Digital Audio In
Digital Audio Out
Description
The EBUIN1/GPIO36, EBUIN2/SCLK_OUT/GPIO13,
EBUIN3/CMD_SDIO2/GPIO14, and QSPI_CS0/EBUIN4/GPIO15
multiplexed signals can serve as general purpose input or can be driven
by various digital audio (IEC958) input sources. Both functionalities are
always active. Input chosen for IEC958 receiver is programmed within
the audio module. Input value on the 4 pins can always be read from the
appropriate GPIO register.
The EBUOUT1/GPIO37 and QSPI_CS1/EBUOUT2/GPIO16
multiplexed pins can serve as general purpose I/O or as digital audio
(IEC958) output. EBUOUT1 is digital audio out for consumer mode,
EBUOUT2 is digital audio out for professional mode. During reset, the
pin is configured as a digital audio output.
4.13 Subcode Interface
There is a 3-line subcode interface on the SCF5250. This 3-line subcode interface allows the device to
format and transmit subcode in EIAJ format to a CD channel encoder device. The three signals are
described in Table 10.
Table 10. Subcode Interface Signal
Signal name
RCK/QSPI_DIN/QSPI_DOUT/GPIO26
QSPI_DOUT/SFSY/GPIO27
QSPI_CLK/SUBR/GPIO25
Description
Subcode clock input. When pin is used as subcode clock, this pin is
driven by the CD channel encoder.
Subcode sync output
This signal is driven high if a subcode sync needs to be inserted in the
EFM stream.
Subcode data output
This signal is a subcode data out pin.
4.14 Analog to Digital Converter (ADC)
The ADOUT signal on the ADOUT/SCLK4/GPIO58 pin provides the reference voltage in PWM format.
This output requires an external integrator circuit (resistor/capacitor) to convert it to a DC level to be input
to the ADREF pin.
The six AD inputs are each fed to their own comparator. The reference input to each (ADREF) is then
multiplexed as only one AD comparison can be made at any one time.
NOTE
To use the ADINx as General Purpose inputs (rather than there analogue
function) it is necessary to generate a fixed comparator voltage level of
VDD/2. This can be accomplished by a potential divider network connected
to the ADREF pin. However in portable applications where stand-by power
SCF5250 Integrated ColdFire® Microprocessor Data Sheet, Rev. 1.1
Freescale Semiconductor
17