AT&T 3B2 Off-Line Diagnostic Manual page 152

Version 3 Hardware System Board Diagnostics - - - - - - - - - - - - - - - - - - - - -
Test Numbers:
Function:
Procedure:
37 through 40
These tests check the ability of the UART B to transmit and receive a character
correctly and to set or reset the Receive Status bit in the Status register of the
UART.
The test procedure is as follows:
1. A character is transmitted.
2. The Receive Status bit is looped on until a time-out occurs or it is set.
3. The validity of the received character is checked if a time-out does not
occur.
4. The receive flag is checked to be cleared upon reading the data.
Hardware Tested: The SCN2681 DUART is checked.
Data Returned: The failing register number and the status of the RCVRDY and XMTRDY
Time-out bits are returned.
Notes: None
Test Numbers: 41 through 47
Function: These tests check transmission at different baud rates on the A side.
Procedure: A one is walked through zeros at baud rates of 110, 300, 1200, 2400, 4800,
9600, and 19200.
Hardware Tested: The SCN2681 DUART is tested.
Data Returned: The failing register number and the status of the RCVRDY and XMTRDY
Time-out bits are returned.
Notes: None
Test Numbers: 48 through 54
Function: These tests check transmission at different baud rates on the B side.
Procedure: A one is walked through zeros at baud rates of 110, 300, 1200, 2400, 4800,
9600, and 19200.
Hardware Tested: The SCN2681 DUART is tested.
Data Returned: The failing register number and the status of the RCVRDY and XMTRDY
Time-out bits are returned.
Notes: None
3-112 OFF-LINE DIAGNOSTIC MANUAL