Nortel Networks Circuit Card System considerations

Page 684 of 906 NT8D41BA Quad Serial Data Interface Paddle Board
553-3001-211 Standard 3.00 August 2005
Other logic on the card includes baud rate generators, RS-232-C driver/
receiver pairs, and the switches and logic needed to configure each UART.
System considerations
In dual-processor systems, the QSDI paddle board will behave differently
depending on which backplane socket it is installed. 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
a socket in the CPU area of the backplane allows it to work only when that
CPU is active.
Figure 162
NT8D41BA QSDI paddle board block diagram
UART
no. 1
UART
no. 2
UART
no. 3
UART
no. 4
UARTs
Address
decode logic
TD
RD
TD
RD
TD
RD
TD
RD
RS-232-C
drivers and receivers
Clock and bit
rate select logic
Processor
bus
553-5986
Port 1
Port 2
Port 3
Port 4
J1
J2