AK4545 Datasheet, PDF (18/33 Pages) Asahi Kasei Microsystems – AC97 AUDIO CODEC WITH SRC AND DIT

[ASAHI KASEI]
[AK4545]
nS/PDIF output
a) Electrical Characteristics
Same as other digital output pins (CMOS level).
S/PDIFout pin is supposed to be connected to optical component only.
b) Outline of S/PDIF Spec.
(1) The channel status of the AK4545 supports consumer mode only. The AK4545 has three-16 bit registers
which keep Copyrights-bit, Category-code bits, Generation-bit, etc. These bits can be changed through AC-
link I/F.
(2) SDATA_IN data or SDATA_OUT data is encoded to appropriate bi-phase signal by internal digital audio
transmitter (DIT) circuit, and is output through S/ PDIFout pin. One of the following audio data streams can
be selected as the input signal to DIT circuit by the setting of internal register.
(a) D/A data from SDATA_OUT (slot3/4)
(b) A/D data to SDATA_IN (slot 3/4)
(c) Slot 7/8 data from SDATA_OUT (In this case, we assume that slot7/8 is original AC-3 encoded data,
and that slot 3/4 is down-mixed AC-3 audio data Therefore, the device supposes data rate of slot 7/8
and slot 3/4 to be same and to be 48kHz . )
(3) Even if A/D and D/A sampling frequency (fs) are different, S/PDIFout circuit works correctly.
BIT_CLK
SYNC
SDATA_OUT
SDATA_IN
RESET#
AC-Link
Interface
AK4545
FIFO
for A/D
FIFO
for D/A
ADC
DAC
S/PDIF OUT
Data of Slot7,8
IO
S/PDIF
Out
IO
Data of Slot3,4
ASLT
AD CLK
DA CLK
I/O
ASLT Data Select
0
0
SDATA_OUT : slot 3, 4
0
1
SDATA_OUT : slot 7, 8 Note
1
X
SDATA_IN : slot 3, 4
Note) DAC rate and S/PDIF rate should be same (48kHz).
MS0058-E-00
- 18 -
2000/11