GS1559 Data Sheet
30572 - 4
July 2005
45 of 74
4.10.2.1 Programmable Ancillary Data Detection
Although the GS1559 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 4-5
).
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 GS1559 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 GS1559 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 GS1559 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 53
).
NOTE 2: See SMPTE 291M for a definition of ancillary data terms.
Table 4-5: Host Interface Description for Programmable Ancillary Data Type Registers
Register Name
Bit
Name
Description
R/W
Default
ANC_TYPE1
Address: 005h
15-8
ANC_TYPE1[15:8]
Used to program the DID for ancillary data detection at
the YANC and CANC output
R/W
0
7-0
ANC_TYPE1[7:0]
Used to program the SDID for ancillary data detection
at the YANC and CANC output.
Should be set to zero if no SDID is present in the
ancillary data packet to be detected.
R/W
0
ANC_TYPE2
Address: 006h
15-8
ANC_TYPE2[15:8]
Used to program the DID for ancillary data detection at
the YANC and CANC output
R/W
0
7-0
ANC_TYPE2[7:0]
Used to program the SDID for ancillary data detection
at the YANC and CANC output.
Should be set to zero if no SDID is present in the
ancillary data packet to be detected.
R/W
0
ANC_TYPE3
Address: 007h
15-8
ANC_TYPE3[15:8]
Used to program the DID for ancillary data detection at
the YANC and CANC output
R/W
0
7-0
ANC_TYPE3[7:0]
Used to program the SDID for ancillary data detection
at the YANC and CANC output.
Should be set to zero if no SDID is present in the
ancillary data packet to be detected.
R/W
0