GS1560A/GS1561 Data Sheet
3.10.2.1 Programmable Ancillary Data Detection
Although the GS1560A/GS1561 will detect all types of ancillary data by default, it
also allows the host interface to specifically program up to five different ancillary
data types for detection. This is accomplished via the ANC_TYPE register
(Table 3-5).
For each data type to be detected, the host interface must program the DID and/or
SDID of the ancillary data type of interest. The GS1560A/GS1561 will compare the
received DID and/or SDID with the programmed values and assert YANC and
CANC only if an exact match is found.
If any DID or SDID value is set to zero in the ANC_TYPE register, no comparison
or match will be made for that value. For example, if the DID is programmed but
the SDID is set to zero, the device will detect all ancillary data types matching the
DID value, regardless of the SDID.
In the case where all five DID and SDID values are set to zero, the
GS1560A/GS1561 will detect all ancillary data types. This is the default setting
after device reset.
Where one or more, but less than five, DID and/or SDID values have been
programmed, then only those matching ancillary data types will be detected and
indicated.
NOTE 1: The GS1560A/GS1561 will always detect EDH ancillary data packets for
EDH error detection purposes, regardless of which DID/SDID values have been
programmed for ancillary data indication, (see EDH CRC Error Detection on
page 58).
NOTE 2: See SMPTE 291M for a definition of ancillary data terms.
27360 - 8 September 2005
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