Functional Description - Nortel Circuit Card Installation Manual

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Functional description

Figure 158
NT8D41AA SDI paddle board block diagram
Address
decode logic
Control
bus
System considerations
553-3001-211 Standard 3.00
NT8D41AA Serial Data Interface Paddle Board
The NT8D41AA SDI paddle board has two asynchronous serial ports. These
serial ports are connected to the I/O panel in the back of the shelf using special
adapter cables. The serial ports can be used to connect the system to a
terminal, a printer, a modem, or to an other system processor.
The SDI paddle board contains two Universal Asynchronous Receiver/
Transmitters (UARTs) and the logic necessary to connect the UARTs to the
system processor bus. See Figure 158. Other logic on the card includes two
baud rate generators, two RS-232-C driver/receiver pairs, and the switches
and logic needed to configure the UARTs.
UARTs
UART
no. 1
UART
no. 2
In dual-processor systems, the SDI paddle board will behave differently
depending on which backplane socket it is installed in. Installing the paddle
board into a socket in the network area of the backplane allows it to work
when either of the system processors is active. Installing the paddle board into
August 2005
RS-232-C
drivers and receivers
Clock and bit
rate select logic
TD
Port 1
RD
(J1)
TD
Port 2
(J2)
RD
553-5980