VS 2001
Technical Handbook
Accessories
P/N: 779-0373/02
Revision 02
Marconi Proprietary information
Page 27
The individual circuits of the Base Band section can be summarised as follows:
•
A microcontroller that has the general control of all the radio activities. It is
supported by a RAM, a FLASH EPROM, 2 EEPROMs and an identification
code generator;
•
Microcontroller interfaces to the FPGA and directly to the R/T card (this
section is included in the microprocessor block);
•
A DSP (with its own RAM) which is interfaced to the A/D and D/A converters
of RX and TX and to the audio signals (from microphone/handset and to
loudspeaker/headset) through the CODEC;
•
An FPGA which acts as a control interface for the R/T card and as an
interface between the DSP and the A/D and D/A converters of the R/T
section. The FPGA also generates all the timing signals. All the timing signals
are derived from a reference clock, set at Fref (see Tab. 2.5), and generated
by an appropriate circuitry.
Since some parts of the Base Band card are powered at 5 V and some others at
3.3 V, there is a level Translator circuit in order to connect them.
Other electronic devices contained on this card are listed as follows:
•
Protection diode against power supply polarity inversion;
•
LC filtering of battery power supply;
•
Main FET switch which interrupts power supply to all equipment circuits;
•
Audio power amplifier to drive the loudspeaker;
•
Stabiliser generating a voltage of +7.2 V used by the R/T card;
•
Stabiliser generating a voltage of +5 V used by the Base Band card;
•
Stabiliser generating a voltage of +3.3 V used by the Base Band card;
•
Stabiliser generating a voltage of +5 V (+5VTLC) used by the Front Panel.
Connection to the R/T card is carried out via the J02 double 36-pin connector (see
2.3.1.2).
Connection with the P.A. card is carried out via the J04 6-pin single comb male
connector (see 2.3.1.2).
2.3.1.1
External connector
The P01 external connector (25-pin male D-type connector) provides the physical
interface between the Base Band card and the external accessories.
The signals, exchanged via this interface, are:
•
User commands (i.e. terminal turning on command, Push-To-Talk (PTT)
command, alarm command)
•
Data with terminal on asynchronous serial line with the possibility of using the
RTS and CTS control signals. The baud rate can be selected at 110, 300,
600, 1200, 2400, 4800, 9600, 14400, 19200, 28800, 38400, 57600 and
115200 bps;
•
Data with terminal on a second asynchronous serial line. The baud rate can
be selected at 9600, 19200, 38400 and 57600 bps;
