GS1560A/GS1561 Data Sheet
3.10.5 Error Detection and Indication
The GS1560A/GS1561 contains a number of error detection functions to enhance
operation of the device when operating in SMPTE mode. These functions, (except
lock error detection), will not be available in either DVB-ASI or Data-Through
operating modes. See DVB-ASI Functionality on page 45 and Data Through Mode
on page 46.
The device maintains an error status register at address 001 called
h
ERROR_STATUS (Table 3-11). Each type of error has a specific flag or bit in this
register which is set HIGH whenever that error is detected.
The ERROR_STATUS register will be cleared at the start of each video field or
when read by the host interface, which ever condition occurs first.
All bits of the ERROR_STATUS register except the LOCK_ERR bit will also be
cleared if a change in the video standard is detected, or under the following
conditions:
•
•
•
RESET_TRST is held LOW
LOCKED is asserted LOW
SMPTE_BYPASS is asserted LOW in slave mode
In addition to the ERROR_STATUS register, a register called ERROR_MASK
(Table 3-12) is included which allows the host interface to select the specific error
conditions that will be detected. There is one bit in the ERROR_MASK register for
each type of error represented in the ERROR_STATUS register.
The bits of the ERROR_MASK register will default to '0' after device reset, thus
enabling all error types to be detected. The host interface may disable individual
error detection by setting the corresponding bit HIGH in this register.
Error conditions are also indicated to the application layer via the status signal pin
DATA_ERROR. This output pin is a logical 'OR'ing of each error status flag stored
in the ERROR_STATUS register. DATA_ERROR is normally HIGH, but will be set
LOW by the device when an error condition that has not been masked is detected.
27360 - 8 September 2005
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