CXD1968AR
Monitoring
Status Monitoring
Transport Stream Lock
This flag indicates that a valid MPEG2 transport stream is available at the CXD1968AR TSDATA
outputs. Transport stream lock can be determined from reading the FEC_STATUS register, or from the
INTERRUPT_SOURCE register. This bit is set in both registers whenever the Reed-Solomon FEC
block has locked and a valid MPEG2 transport stream is now ready for output. Should the transport
stream lose lock, then a TS lost lock flag bit is set in the FEC_PARAMS and INTERRUPT_SOURCE
registers.
FEC Lock
FEC lock indicates that the Reed-Solomon FEC block has a coded MPEG2 transport stream at its input,
which it is trying to decode. FEC lock can be determined from reading the FEC_STATUS register.
AGC Lock
The AGC lock flag in the COR_STAT register can be used to check that the input signal level is not
varying and is not too high or too low (a high-level signal will cause distortion problems, and a low-level
signal will suffer from quantization noise).
Core State Machine
The COFDM demodulator contains a state machine, which can be used to gain information as to why
the CXD1968AR has not locked on to an incoming OFDM signal. The core has the following states:
0000
0001
0010
0011
0100
0101
0110
State machine not forced
WAIT_TRL
WAIT_AGC
WAIT_SYR
WAIT_PPM
WAIT_TPS
MONITOR _TPS
State 0: IDLE
Core is disabled.
State 1: WAIT_ TRL
State 2: WAIT_AGC
Core is calculating a value to be used later.
Core is waiting for input signal levels to stabilize to an acceptable value
before attempting to demodulate the incoming signal.
State 3: WAIT_SYR
AGC has locked, waiting for the core to determine the guard interval and its
position.
State 4: WAIT_PPM
State 5: WAIT_TPS
Waiting for the pilot processing module to find the pilot carriers.
Waiting for the core’s TPS decoder to acquire frame sync
(which determines the symbol number).
State 6: MONITOR_TPS Signal ready to be fed to the Viterbi decoder, continue to monitor the TPS
data for parameter changes.
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SONY [ SONY CORPORATION ]
