LC89057W-VF4A-E Datasheet, PDF (31/59 Pages) Sanyo Semicon Device – Digital Audio Interface Transceiver

LC89057W-VF4A-E
10.7 IEC61937, DTS-CD/LD Detection Flag Output
• _{A function to output IEC61937 and DTS-CD/LD detection flags for Non-PCM data is provided.}
______
• When the UNPCM of non-PCM signal output setting is selected through the INT output contents setting, an interrupt
______
signal is output from INT detecting an IEC61937 or DTS-CD/LD sync signal. Reading output register from this
information can see details of Non-PCM signal.
• _{When bit 1 of channel status is non-PCM data ("1"), the IEC61937 sync signal is detected and output. If bit 1 is PCM}
data, the IEC61937 sync signal is not output.
• _{DTS-CD/LD sync signal detection is done based on the sync pattern and the base frequency. DTS-ES data detection is}
output when the DTS5.1 channel sync signal is detected and the DTS-ES sync pattern is verified.
• _{The IEC61937 and DTS-CD/LD detection flags are cleared when fs have changed or a PLL lock error or data error}
has occurred.
• _{Since the DTS sync signal is provided within the audio data, digital data with the same code as the DTS sync signal}
may exist in rare cases for regular CD/LD records that are not recorded in the DTS format. Protection using the sync
pattern or base frequency is provided so that such data is not misinterpreted as DTS-CD/LD detection flags. The
detection sequence is shown below.
Input data
Bit 1detection
NO
Bit 1=1
YES
PaPb
detection
YES
Frame counter
start
NO
Frame counter
reset
DTS-CD/LD SYNC
NO
detection
YES
Frame counter
start
Frame counter
reset
PaPb detection
NO
during 4096
frames
YES
IEC61937 flag OK
INT lowered
IEC61937 flag
not valid
INT lowered
PaPb detection
during 4096
frames
YES
IEC61937 data hold
NO
* Depending on the frame count,
· the subsequent detection count
· is expanded up to ×2.
· Periodic fluctuation is supported.
1st count
512 
1024 
2048 
4096 
2nd count
512 or 1024
1024 or 2048
2048 or 4096
4096
Frame count
512,1024,2048,4096
NO
SYNC detection
YES
DTS-CD/LD flag OK
INT lowered
DTS-CD/LD flag
not valid
INT lowered
*
Frame count hold
x2 count detection
expansion
*
Frame count
NO
512,1024,2048,4096
SYNC detection
YES
DTS-CD/LD
data hold
Figure 10.16 IEC61937 and DTS-CD/LD Data Detection Sequence
No.7202-31/59