GS9060 Data Sheet
3.10.5.4 Ancillary Data Checksum Error Detection
The GS9060 will calculate checksums for all received ancillary data and compare
the calculated values to the received checksum words. If a mismatch is detected,
the error is flagged in the CS_ERR bits of the ERROR_STATUS register.
Although the GS9060 will calculate and compare checksum values for all ancillary
data types by default, the host interface may program the device to check only
certain types of ancillary data checksums.
This is accomplished via the ANC_TYPE register as described in Section 3.10.2.1
on page 37.
3.10.5.5 TRS Error Detection
TRS errors flags are generated by the GS9060 when:
1. The received TRS timing does not correspond to the internal flywheel timing;
or
2. The received TRS hamming codes are incorrect.
Both 8-bit and 10-bit SAV and EAV TRS words are checked for timing and data
integrity errors. These are flagged via the SAV_ERR and/or EAV_ERR bits of the
ERROR_STATUS register.
Timing-based TRS errors will only be generated if the FW_EN/DIS pin is set HIGH.
3.10.6 Error Correction and Insertion
In addition to signal error detection and indication, the GS9060 may also correct
certain types of errors by inserting corrected code words and checksums into the
data stream. These features are only available in SMPTE mode and
IOPROC_EN/DIS must be set HIGH. Individual correction features may be
enabled or disabled via the IOPROC_DISABLE register (Table 3-13).
All of the IOPROC_DISABLE register bits default to '0' after device reset, enabling
all of the processing features. To disable any individual error correction feature, the
host interface must set the corresponding bit HIGH in the IOPROC_DISABLE
register.
3.10.6.1 Illegal Code Remapping
If the ILLEGAL_REMAP bit of the IOPROC_DISABLE register is set LOW, the
GS9060 will remap all codes within the active picture between the values of 3FCh
and 3FFh to 3FBh. All codes within the active picture area between the values of
000h and 003h will be re-mapped to 004h.
In addition, 8-bit TRS and ancillary data preambles will be remapped to 10-bit
values if this feature is enabled.
22208 - 8 January 2007
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