User's Manual

30 kW S-BAND/U ANTENNA GROUP
FUNCTIONAL DESCRIPTION
3.7 Rev. C
3 .3 .3 .2 Micropr ocessor and Ga t e Arr a y
3 .3 .3 .2 .1 Gener a l de script ion
The heart of RTM CONT B Board, and generally of whole Transceiver, is an
advanced 8 Bit MCU, (Micro-controller Unit), with highly sophisticated, on chip,
peripheral capabilities. It performs the following functions:
- managing all functions of the Transceiver Unit on the basis of
commands/data from the Display Unit
- preparing the feed-back signals to be sent out to the
Indicator unit
- executing all internal processing to ensure the Transceiver
Unit control and monitoring
The Microprocessor used in the Board is the 68HC711E9 and the on-chip
memory system includes 8 Kbytes ROM, 512 bytes EEPROM, 256 bytes RAM
and a Gate Array type XCS10XL. Major peripheral functions are provided on-
chip.
An eight-channel A/D Converter is included, with eight bits of resolution.
Asynchronous Serial Communications Interface (SCI) and a separate
synchronous Serial Peripheral Interface (SPI) are included.
The main 16-bit, free-running Timer system has three input-capture lines, five
output-compare lines and a Real Time Interrupt function. An 8-bit pulse
Accumulator sub-system can count external events or measure external
periods. A Watch-dog system protects against software failures.
The Transceiver unit management is performed by the Microprocessor, which
does not require any external PROM or RAM elements: its own memory, in fact,
has sufficient capacity to store both the Operative Program and Temporary
data. The necessary clock pulses are generated by a 10 MHz crystal oscillator.
In Chapter 9, Figure 9.1.13 are displayed the Microprocessor and the Gate
Array general configuration, the main sub-systems and how they relate to the
pins of the MCU.
3 .3 .3 .2 .2 Functions Pe rform ed
The main functions performed by the Microprocessor with the by Gate Array, on
the basis of commands and selections, Remote (from Display Unit) or Local
(Through the Selectors) are:
- to initialise the Transceiver operations
- to generate the trigger pulse for POWER MOS Board and the
trigger (TR) and pre-trigger, (PRTR) pulse for both the
Display Unit and the P.M. function
- to generate the PRESTC waveform for the NIFB Assy (STC)
and the selection commands for band-width of Receiver
- to generate:
. the VCO forwarded to Mixer