3.4
Station Control Subsystem
3.4.1
Description
The Station Control Subsystem is described in this section. A general description, identification of
controls, indicators, and inputs/outputs, a functional block diagram, and functional theory of operation
are provided.
The Controller circuitry performs the digital signal processing, data formatting and audio routing for the
station and provides the external interfaces to the rest of the site.
The Controller section consists of 7 main ICs. These are:
• Texas Instrument DM8148 Host/DSP Processor
• EMMC Flash memory
• DDR3 memory
• Texas Instruments Power Management IC
• NOR Flash
• 2-TI AIC3204 Codecs
General controller functionality includes:
• Data and Control interface to the transceiver ICs
• Audio interface with CODEC ICs
• UART interface to expansion board
• Intermodule communication (SPI, I2C)
• Two Ethernet ports
• USB Device port
• USB Host port
• External physical interfaces (connectors, LEDs, external references etc.)
• Station Reference Control
3.4.2
High Stability Reference Block
The high-stability reference block can be used to enhance the 0.5 ppm Voltage Controlled
Temperature Compensated Crystal Oscillator. The block diagram is shown below in Figure 9: High
Stability Reference Circuit on page 51. An external reference can be applied to lock the on board
VCTCXO. This function can be enabled via the customer programming software. The connection is
made via a cable connecting a BNC connector on the rear panel to a connector on the modem module.
The location of the connector on the modem module can be found in Figure 8: Modem Module
Connector Locations on page 48.
Figure 9: High Stability Reference Circuit
19.2MHz
VCTCXO
DAC Output
from
Transceiver IC
PLL
Ref_Lck_Det
Lock
Detect
Tune
STD_EN
VCTCXO
LOOP
FILTER
Phase
Detector
Loop Divider
SPI
External
Reference
Chapter 3: SLR 5000 Series Modem
Motorola Solutions Confidential
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