WM8804
Production Data
w
PD Rev 4.1 September 2007
38
S/PDIF RECEIVER STATUS FLAGS
There are several S/PDIF receiver status flags which are recorded by the WM8804. The flags are
described in Table 45. These flags are available via GPIO pins or status registers.
FLAG DESCRIPTION
VISIBILITY
UNLOCK Unlock
Flag
Indicates that the S/PDIF Rx clock recovery circuit is unlocked.
0 = Locked onto incoming S/PDIF stream.
1 = Not locked onto the incoming S/PDIF stream.
S/PDIF Status
Register,
GPO,
CSB –hardware mode
INVALID Invalid
Flag
Indicates that recovered S/PDIF data is marked as invalid.
0 = Data marked as valid
1 = Data marked as invalid
Interrupt Status Reg
TRANS_ERR Transmission
Error
Flag
Indicates that a transmission error has occurred. This signal is asserted
when the preamble sequence is incorrectly received or there is a parity
error or a bi-phase mark encoding error.
0 = No error detected in transmission
1 = Error in transmission
Interrupt Status Reg,
GPO,
SCLK –hardware
mode
AUDIO_N Audio
Status
Flag
Recovered Channel Status bit 1.
0 = Data word represents audio PCM samples.
1 = Data word does not represent audio PCM samples.
Channel Status
Register,
S/PDIF Status
Register
PCM_N Non-PCM
Flag
Indicates that non-audio code (defined in IEC-61937) has been detected.
0 = Sync code not detected.
1 = Sync code detected – received data is not audio PCM.
S/PDIF Status
Register
ZEROFLAG Zero
Flag
Indicates detection of 1024 consecutive all zero frames
0 = 1024 consecutive all zero frames not detected
1 = 1024 consecutive all zero frames detected
GPO
CPY_N Non-Copyright
Flag
Recovered Channel Status bit 2.
0 = Copyright is asserted for this data.
1 = Copyright is not asserted for this data.
Note this signal is inverted and will cause an interrupt on logic 0.
Channel Status
Register,
S/PDIF Status
Register,
GPO
REC_FREQ[1:0]
Recovered Frequency Flag
Indicates recovered S/PDIF clock frequency:
00 = 192kHz
01 = 96kHz or 88.2kHz
10 = 48kHz or 44.1kHz
11 = 32kHz
S/PDIF Status
Register
INT_N Interrupt
Signal
0 = Interrupt has occurred
1 = No interrupt has occurred
GPO
V
Recovered validity bit for current sub-frame
GPO
U
Recovered user bit for current sub-frame
GPO
C
Recovered channel status bit for current sub-frame
GPO
SFRM_CLK Sub-frame
clock.
1 = Current sub-frame is sub-frame A
0 = Current sub-frame is sub -frame B
GPO
192BLK
Start OF 192 Frame Sequence Flag
Indicates start of 192 frame block. Asserted duration of frame 0.
GPO
GEN_FLAG
General Error Flag
Logical OR of TRANS_ERR, NON_AUDIO and UNLOCK. Used only in
Hardware Control Mode
GPO0 - hardware
Mode
