Technical Manual

ATLAS 4500 Multimode Station Technical Manual July 2016 A-15
Audio Logic Board Appendix A - 700/800 MHz Circuit Descriptions
The Controller sends serial data on 3 lines to the PA 7 bit attenuator ATN1, ATN2,
ATN3 for SI, CLK, LE pins on the attenuator IC.
The Controller has an input port for the temperature sensor sending a pulse width
modulated signal.
A.4.2.8 Firmware
The Controller flash contains following:
• Gateway operational software to obey command protocol from the DSP. DSP
sends commands to set up RF characteristics, modulation etc.
• PA power control software and temperature sensing. Fan control.
• Debug software to allow control through the PC terminal program.
• Alarm points and monitors alarms and takes corrective action
• Controls interfaces with Exciter for frequency setting and PTT indication
• Controls EEPROM reading and writing from various modules. Allows it to be
controlled from the Debug point initially. Later DSP can select.
• Configuration data, serial number etc. Plug and play system for all modules.
Reads config data from all modules.
• Other operational software.
A.5 Audio Logic Board
A.5.1 General Description
The Audio Logic board is the main controller for the base station.
It sends and receives serial control to the Controller using a defined protocol.
It communicates data with the Ethernet link receiving and sending data to its
network.
The TX data encoding, modulation shaping, RX clock recovery, demodulation etc
is done by the hardware and programming.
The TX modulation data is sent synchronously through the I2SCLK, I2SDAT,
ISFRM lines to the Exciter through the Controller board.
The RX modulation is through 90 MHz IF ports, main and diversity.