Development test port connector

The development test port connector on the AG 2000 board (shown in the following illustration) gives developers easy access to the transmit for ports 7 and 8 and the receive for port 8 for fast debugging of applications.

The connector is a hardware interface composed of a 4-pin connector and amplifier circuitry provided on the AG 2000 board that allows audio ports from port 7 and port 8 to be summed together and played out. Audio can be recorded into port 8.

Connect the Line out to an amplified speaker and listen to audio. Connect a device, such as a tape player, to TST_IN to record messages or prompts on the system.

The following signals are available on the connector: summation of Trunk 7 and Trunk 8 out, Trunk 8 in, and Gnd.

The output audio amplifier has a 100 Ohm output impedance. It is designed to interface to an amplified speaker. If it is connected to an un-amplified speaker, the audio has a very low output level.

You can listen to two different digital audio streams simultaneously. The development test port connector has an on-board hardware summing amplifier. If you play audio from one stream to port 8 (stream 1:7) and the audio from another stream to port 7 (stream 1:6), the resulting audio is summed by the hardware. While this is occurring, audio cannot be recorded in. Therefore, simultaneous play and record is not possible.

A 0.774 VRMS signal coming in on TST_IN records at a 0 dBm signal into the CODEC. Speech levels should not have peaks exceeding this level. The average speech level should be approximately 0.1 VRMS at TST_IN. The input impedance is 20K Ohms.

The following illustration shows the pinout and mating connector for the test port connector:

The mating connector is a Molex 50-57-9404. The pin that must also be inserted into the connector is the female pin (Molex 70058).