Nortel Networks 553-3001-211 manual System considerations, NT8D41AA SDI paddle board block diagram

Page 658 of 894 NT8D41AA Serial Data Interface Paddle Board

Functional description

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 155. 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.

Figure 155

NT8D41AA SDI paddle board block diagram

	UARTs	RS-232-C
		drivers and receivers
	UART	TD	Port 1
		RD
			(J1)
	no. 1
	UART	TD	Port 2
		RD	(J2)
	no. 2
Address		Clock and bit
decode logic		rate select logic
Control			553-5980
bus

System considerations

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

553-3001-211 Standard 2.00 September 2004