Hi Traveler,
You're right. The I²C-bus is for LCD/LED-, keypads-, converter-
and EEPROM-controls and A-to-D-, D-to-A converters.
My "bus" fault.
The MCV5249 got analog/digital audio-I/Os channels and the
UDA1380 too. I've checked the MCF5249 evaluation board circuit
block-diagram and there's no direct use of the MCF5249 IEC958
I/O channels on it. So which layout uses iriver?
1) Serial audio interfaces (IIS/EIAJ)
or
2) Digital audio interfaces (IEC958)
I think iriver uses the serial audio interfaces (I²S bus) only (1.5.9).
On the circuit layout, the UDA1380 is placed near the digital and
analog connectors.
An short cut out of the Product Brief, MCF5249PB/D, Rev. 0, 3/2002
1.5.9 Serial Audio Interfaces
The MCF5249 digital audio interface provides four serial Philips IIS/Sony EIAJ interfaces. One interface
is a 4-pin (1 bit clock, 1 word clock, 1 data in, 1 data out), the other three interfaces are 3-pin (1 bit clock,
1 word clock, 1 data in or out). The serial interfaces have no limit on minimum sampling frequency.
Maximum sampling frequency is determined by maximum frequency on bit clock input. This is 1/3 the
frequency of the internal system clock.
1.5.10 IEC958 Digital Audio Interfaces
The MCF5249 has two digital audio input interfaces, and one digital audio output interface. There are four
digital audio input pins, two digital audio output pins. An internal multiplexer selects one of the four inputs
to the digital audio input interface.
There is one digital audio output interface but it has two IEC958 outputs. One output carries the professional
“c” channel (Channel Status), and the other carries the consumer “c” channel. All other bits (audio data, user
channel bits, validity flag, etc) are identical.
The IEC958 output can take the output from the internal IEC958 generator, or multiplex out one of the four
IEC958 inputs.
1.5.11 Audio Bus
The audio interfaces connect to an internal bus that carries all audio data. Each receiver places its received
data on the audio bus and each transmitter takes data from the audio bus for transmission. Each transmitter
has a source select register.
In addition to the audio interfaces, there are six CPU accessible registers connected to the audio bus. Three
of these registers allow data reads from the audio bus and allow selection of the audio source. The other three
registers provide a write path to the audio bus and can be selected by transmitters as the audio source.
Through these registers, the CPU has access to the audio samples for processing.
Audio can be routed from a receiver to a transmitter without the data being processed by the core so the
audio bus can be used as a digital audio data switch. The audio bus can also be used for audio format
conversion.
END CUT ----------------
I've read some sections of the MCF5249 user manual. So mobil audio designer can program (activate)
the IEC985 or the I²S (or use both?)
With the I²S bus they are a more compatible to other I/O techniques ... I guess.
cheers Juergen
iHP@lounge
www.ihplounge.com
