User Manual

DXU-21
• I2C controller
• SDRAM memory
• FLASH memory
• CPU
• Compact Flash Card
4.2 Communication Switch System
This system block contains circuits that handle traffic between the BSC and
the dTRUs.
4.3 Transmission Interface Controller
This part contains circuits for four transmission ports and the transmission
interface controller, which controls the traffic for all four transmission ports.
The bit rate is SW controlled. Two speeds are available: E1 (2.048 Mbit/s)
or T1 (1.544 Mbit/s).
4.4 Power Supply
The power supply delivers all the voltages necessary for the DXU-21. The input
voltage, +24 V DC, is supplied through backplane connectors.
4.5 Timing System
The timing system is used to generate timing for the TRUs.
4.6 Miscellaneous Logic
This function contains the following:
• System voltage measurement
• Temperature measurement
• Power on reset
4.7 Compact Flash Card
The removable Compact Flash Card permits quick and easy change of the DXU.
6 (10)
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N/LZT 720 0244 Uen R3A