Dolby Laboratories DP572, DP571 user manual Digital Outputs, PCM Delay Output, LTC Output

Dolby E Multichannel Distribution System User Manual DP572 Dolby E Decoder

The state of the pins is normally high (internal pull up), and they detect a high-to-low transition. A held contact closure between pins 7 and 9 (ground) or pins 8 and 9 is required to activate a function. A low-to-high transition (i.e., a switch release) restores the External Standby setting. Table 4-2shows the function of the two GPI pins on the DP572.

Table 4-2Status port output routing mode selection

Ctrl in pin 8	Ctrl in pin 7	PCM Chan Config
		Output Routing Mode
High	High	External Standby
High	Low	Voiceover
Low	High	Switched Out
Low	Low	Reserved

4.1.9Digital Outputs

A maximum of eight channels of decoded audio are supplied on the four AES3 outputs. A second electrically isolated output is supplied for each channel pair.

Note: The digital outputs are electrically separate, not passive loop-through connections, so there is no need to terminate an unused output.

4.1.10PCM Delay Output

Encoding delay is added to the PCM signal which is then transmitted from the PCM Delay Out connector. The DSP subsystem calculates the delay equivalent to the main channel latency and applies it to the PCM Delay Out. If PCM bypass mode is enabled, the delay matches that of the bypass channel.

4.1.11LTC Output

After de-multiplexing timecode information from the Dolby E stream, the DP572 provides a standard SMPTE LTC signal.

4-5