4

NOTICE

EXAR Corporation reserves the right to make changes to the products contained in this publication in order to

improve design, performance or reliability. EXAR Corporation assumes no responsibility for the use of any

circuits described herein, conveys no license under any patent or other right, and makes no representation that

the circuits are free of patent infringement. Charts and schedules contained here in are only for illustration

purposes and may vary depending upon a user’s specific application. While the information in this publication

has been carefully checked; no responsibility, however, is assumed for inaccuracies.

EXAR Corporation does not recommend the use of any of its products in life support applications where the

failure or malfunction of the product can reasonably be expected to cause failure of the life support system or

to significantly affect its safety or effectiveness. Products are not authorized for use in such applications unless

EXAR Corporation receives, in writing, assurances to its satisfaction that: (a) the risk of injury or damage has

been minimized; (b) the user assumes all such risks; (c) potential liability of EXAR Corporation is adequately

protected under the circumstances.

Copyright 2009 EXAR Corporation

Datasheet April 2009.

Reproduction, in part or whole, without the prior written consent of EXAR Corporation is prohibited.

DATA COMMUNICATIONS APPLICATION NOTE

DAN 200

Here is an example to initialize multidrop mode with auto address detection:

write(LCR, 0xBF);

write(EFR, 0x30);

//EFR[4] = 1 to enable access to MSR bit-6;

//EFR[5] = 1 to enable the special character detect feature;

write(XOFF2, 0xAA); //Set the desired address to 0xaa (or other values for your application);

write(LCR,0x3B);

//Force parity 0 to detect address byte;

//Set data format 8-bit data, 1-bit stop

write(MSR, 0x60);

//Enable 9-bit mode & Disable RX

write(IER, 0x4);

//Enable LSR interrupt

When a matching target address byte is received, single channel XR16Mxxx UART family will enable receiver

to start receiving data automatically. When a new address byte is received that does not match the target ad-

dress byte in XOFF2 register, the receiver will be disabled automatically.

4.0 TECHNICAL SUPPORT