User's Manual

Model 1150A DVOR
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.
2-55
2.3.2.17.2
Monitor CCA Detailed Circuit Theory
The microcontroller used on the Monitor CCA is in a product category called digital signal processor (DSP) that
utilizes external flash ROM, non-volatile RAM (NVRAM), synchronous dynamic RAM (SDRAM), a voltage
supervisor/watchdog reset circuit, and an oscillator to form the core microcomputer. The DSP also includes a direct
memory access (DMA) controller, serial ports, and general purpose input/output (I/O). Microcomputer peripherals
include a real-time clock (RTC), universal asynchronous receiver/transmitters (UARTs), a parallel port interface
(PPI), bus buffers, and more general purpose I/O.
RF
Switch
U31
4 pole BPF
fo=113MHz
BW=20MHz
Gain=-2.6dB
1st LO
(Transmit Frequency-45MHz)
+17dBm
45 MHz IF
MX2
Level 10
44.875MHz
Crystal Oscillator
10dBm
From Y4, U42
ADC
fs=400KHz
U24
125 KHz IF
Slave DSP
U75
Pin=+10dBm
to -35dBm
Op Amp
U20
Gain=10.2dB
Crystal Filter
4 pole
fo=45 MHz
BW=30KHz
LNA
U43
Gain=22dB
LNA
U38
Gain=22dB
Pin=-2dBm
Vref=1V
-3dB
Synth IC
U30
TCXO
U36
Loop Filter
C100,C104, R33
Buffer/
Amp
U34
VCO
Y2-
LNA
LNA
Synthesizer
Digital
Attenuator
5 bit, 32 dB
Field Monitor 1
Field Monitor 2
Selectable
0/-16dB Attenuator
U32,U33,U35
L4 thru L6
MX1
Y3
U40
U61
Gain= 22 dB
U60
Gain= 22 dB
Figure 2-21 Monitor Receiver, Block Diagram
The U6 DSP is one of two DSPs on the Monitor CCA. The U6 DSP utilizes external flash ROMs (U1 and U2) that
contain the operating instructions for the DSP. The U6 DSP utilizes NVRAM (U3) that retains settings even without
power applied to the Monitor CCA. The U6 DSP also uses SDRAM (U5) for temporary storage and execution
RAM. The U6 DSP program instructions are loaded from the flash memory U1 and U2 at power up and then run out
of internal RAM within the U6 DSP or in the slower SDRAM (U5). The U6 DSP includes internal, direct memory
access (DMA) controller, serial ports, and general purpose input/output (I/O).
The U6 DSP’s flash ROM is factory programmed using the J1 SPI boot header while factory debug is accomplished
using the J8 emulator header, and the J9 debug header. These connectors and headers are not be used after factory
testing is completed.
Buffer circuits U8, U9, U11, U12, and U13 are used to buffer the U6 address and data lines for use within the
Monitor circuit card.