Hitachi DV-C605U Service Manual page 78

5-7-2 DVD Audio Output
ZIC2, 3 (LOCAL DRAM)
AUDIO INPUT
BUFFER
AUDIO OUTPUT
BUFFER
1) Compressed Data
The audio data inputted to ZIC1 (ZiVA4.1) A/V decoder is divided into compressed data and uncompressed data.
It is compressed data that is compressed with multi-channel audio data such as Dolby digital, MPEG, DTS, etc. The
compressed data inputted to ZIC1 (ZiVA4.1) is converted into the uncompressed data of 2, 4, and 6 channels
through ZiVA4.1 built-in audio decoder and is outputted to Data 0, 1, 2, and 3 through digital audio interface.
The compressed data is transmitted to external AC-3 amplifier or MPEG/DTS amplifier as IEC-958/1937
transmission data format compressed by ZiVA4.1 built-in IEC-958 output process.
2) Uncompressed Data
The uncompressed data is that data isn't compressed, so it is called CD-DA, LPCM data.
The 2 channels data is converted through audio decoder 2-channel data and Data 0 and Data 1 are outputted in
digital audio interface.Via IEC-958 output process, they is transmitted to digital amplifier or AC-3/MPEG/DTS
amplifier built in the external digital input source with IEC-958/1937 transmission format.
Source Data Types :
MPEG-1,-2, Dolby Digital,
CD-DA, LPCM
HOST or DVD/CD
INTERFACE
Compressed Data
(MPEG, Dolby Digital),
CD-DA, LPCM
AUDIO DECODER
(MPEG, DOLBY DIGITAL,
CD-DA, LPCM
Fig. 5-23 Audio Decoder and Output Interface Datapath
ZIC1 (ZiVA4.1 ; A/V DECODER)
IEC-958/1937 IEC-958/1937
OUTPUT PROCESS INTERFACE
2-Channel LPCM, Decoder
Dolby Digital, Decoded MPEG
Uncompressed 16- or 24-bit
LPCM camples at
fs=44.1,48,96kHz
2-, 4, or 6-
DIGITAL AUDIO
CHANNEL OUTPUT
INTERFACE
PROCESS
Circuit Descriptions
EXTERNAL
RECEIVER
or
DECODER
(IEC-958/1937)
AUDIO
DAC
5-19