Reference Manual

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EN/LZT 720 0244 R1A
Electrically, the DXU-21 consists of the following main blocks:
• CPU system
• Communication switch system
• Transmission interface controller
• Power supply
• Timing system
• Miscellaneous logic
• Compact Flash Card
4.1 CPU System
The heart of the DXU-21 is a 32-bit embedded controller with a PPC 405
processor core with interfaces to a wide range of peripherals.
The CPU system consists of:
• I
2
C controller
• Ethernet 10/100 Mbit/s (full-duplex) controller, MAC
• SDRAM memory
• FLASH memory
• ASIC GARP
• 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 links and the transmission
interface controller, which controls the traffic for all four transmission links.
The bit rate is SW controlled. Two speeds are available: E1 (2.048 Mbit/s) or
T1 (1.544 Mbit/s).