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.

Development test port connector on the AG 2000 board

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:

Pinout for the development 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).