Dolby Laboratories S01/13621 - Manual (Page 17)

Dolby Installation Guidelines Unit Connections and Dimensions
2-7
General Purpose Status Output Port (GPI/O Out)
Table 2-3 Pin Connections of GPI/O Out Port
Pin Connection Comments
1 Fault Power supply or processor/memory fault
2 Lock Valid input and clock sources present and stable
3 Pass-through Valid AC-3 input signal being passed through
4 Encoding AC-3 encoding of input signal active
5 User Preset 1 User Preset 1 selected
6 User Preset 2 User Preset 2 selected
7 User Preset 3 User Preset 3 selected
8 User Preset 4 User Preset 4 selected
9 Ground
Pin 1 This output corresponds to the front-panel Fault LED. When a power
supply or internal hardware fault is detected, the Fault LED illuminates
and the corresponding output signal goes low. When no fault is detected,
the LED does not illuminate and the output signal remains high.
Pin 2 This output reports the status of both the selected input source and clock
source. A high level on this signal indicates that both sources are “valid”
(i.e., locked and stable). A high level does not guarantee a valid output,
only that the input state is valid. A low level will imply that a valid output
is not being produced.
Pin 3 This output reflects the status of Pass-Through mode. A high level
indicates that pass-through is not active. A low level indicates that pass-
through is active (i.e., that a valid encoded bitstream is being passed
through).
Pin 4 This output reflects the state of the Dolby Digital (AC-3) encoding
process. A high-level output indicates that the Dolby Digital encoding
process is not active. A low-level output indicates that the Dolby Digital
encoding process is active. (This includes test tone modes.)
Note: The combination of the pass-through and encoding outputs indicates the DP569
output status. A low level on either output means that the DP569 is producing a valid
encoded output signal.
Pins 5-8 These outputs are directly tied to the respective front-panel preset LEDs.
An active preset state causes the corresponding preset LED to illuminate,
and the corresponding output signal to be low. When the corresponding
preset state is not active, the output will be high.