User's Manual

Model 1150A DVOR
2-34 Rev. - November, 2008
This document contains proprietary information and such information may not be disclosed
to others for any purposes without written permission from SELEX Sistemi Integrati Inc.
Decoding of the address space used by the U8 microcontroller is provided by decoders U23, U24, U21, and U18. All
decoder outputs are used for on-board devices except for U24-10, named ~EXT_CS. This output defines the address
space that is used to decode the Facilities CCA devices. Buffers U43 and U44 establish an 8-bit asynchronous bus
for communications to/from the Facilities CCA. The inputs and outputs of buffers U43 and U44 as well as
~EXT_CS route to connector P2.
The U8 microcontroller has a synchronous serial port controller (SPORT) that is used for communications to the off-
board battery charge / power supply controller or controllers (Spare Slot). The SPORT signals are buffered by U42
before connection to P2.
2.3.2.10
Facilities CCA Theory
Refer to Figure 2-13. The Facilities CCA provides system I/O for the RMS CCA. Many of the inputs and outputs of
the Facilities CCA eventually connect to the Interface CCA after routing through the Control Backplane CCA.
System_1 and system_2 battery-backed power supplies (nominally 48VDC) enter connector P2 where they are
diode-OR’D together and regulated down into several lower voltages; including +24V, ±15VDC, ±12VDC, +5VDC,
and +3.3VDC.
U1 and U7 DC-DC converters regulate the +48V down to +24V and +5V respectively. The +24V supply is routed
out connector P2 for powering the Interface CCA. The +5V supply powers several on-board digital and analog
integrated circuits as well as powering DC-DC converter PS1 to create ±15VDC. Several linear regulators then
create the ±12VDC supplies from the ±15VDC for powering RS232 integrated circuits and the analog signal
processing system.
All power supplies, including the system_1 and system_2 supplies, can be monitored by the RMS CCA through the
analog-digital converter. The RMS CCA will light on-board PWR_OK indicator CR24 if all supplies are within
range. The ~TEST signal, which originates at the LCU CCA and enters on P2-B8, will light all on-board indicators
when active. The ~TEST signal will also cause audio to be emitted from speaker SPK1 when active.
The ~MRESET signal, which originates at the LCU CCA and enters via P1-B16, resets U8 when active. U8 outputs
~RESET, which clears the outputs of all on-board latches. ~RESET is also asserted by U8 if the +3.3V supply drops
too low.
An asynchronous data and address bus provided by the RMS CCA enters via DIN41612 connector P2. The address
bus is decoded into 10 segments for input buffers and output latches. Input buffers are the U27 A-D converter bus,
U28 and U29 system configuration switches, U31 amplifier powers status, U32 monitor powers status, U18
frequency configuration switches, and U37 TACAN antenna status (not used). The output latches are U22 A-D
converter control, and U23 Ident tone multiplexer control.
As mentioned previously, all power supplies can be monitored by the RMS CCA through on-board U26 A-D
converter as well as the U30 voltage reference, exterior and interior temperatures, ten spare analog inputs, and four
spare digital inputs. Exterior and interior temperatures originate at the Interface CCA and are conditioned by U19:A
and U19:B operational amplifiers. The spare analog inputs and spare digital inputs also originate at the Interface
CCA. All of these analog signals are switched through U20 and U21 multiplexers to the single channel A-D
converter and read digitally via buffer U27.
The system configuration switch signals, SCON0 through SCON15, originate on the Control Backplane CCA and
enter via DIN41612 connector P1. Two of these configuration switches, DIALUP/~EXT and DED/~RADIO,
determine whether U12 and U14 on-board modems or external modems connected to the Interface CCA are active.
If the U12 and U14 modems are selected, they communicate to the RMS CCA serially once their TTL signals are
converted to RS232 by U11 and U13. The U12 and U14 modems each have a speaker output which is multiplexed
through U16 to the U15 amplifier and SPK1 speaker. Both U12 and U14 modems have on-board tip and ring
transient voltage suppression (TVS) before eventually routed to the Interface CCA and more TVS protection.