Nortel Circuit Card Installation Manual page 393

Figure 83
MSDL block diagram
CPU Bus
MPU Bus
DMA
Arbitrator
Address Buffer and
Decoding Logic
Shared Resource
Arbitrator
MPU Address
Decoding Logic
Micro Processing Unit
(68020 MPU)
Memory
Parallel I/O
Controller
RS-232
RS-232/422
Transceiver
Transceiver
Monitor Port Port 0
NT6D80 MSDL card
Control and Data
Transceivers
Interface Registers
Memory Address
Counter & Buffer
Integrated Serial Communication Controllers
RS-232/422 RS-232/422
Transceiver Transceiver
Port 1
Circuit Card
Page 393 of 906
Address Bus
Control Bus
Data Bus
Shared Memory
Address Bus
Control Bus
Data Bus
RS-232/422
Transceiver
Port 2 Port 3
553-5432
Description and Installation