AT&T 3B2 Off-Line Diagnostic Manual page 83

- - - - - - - - - - - - - - - - - - - - - Version 2 Hardware System Board Diagnostics
Test Numbers: 53 and 54
Function: These tests check transmission at 1 and 1.5 Stop bits on the B side (2 already
tested).
Procedure: Walk a one through zeros at 1 and 1.5 Stop bits.
Hardware Tested: The UART and associated Control registers are tested.
Data Returned:
Notes:
Test Numbers:
Function:
Procedure:
Raw Data: 1
=
XMTRDY Status register time-out error is returned.
2
=
RCVRDY Status register time-out error is returned.
3
=
Improper data detected is returned.
None
55 and 56
These tests check bits, other than Error bits, of the Status register on the A side.
Test 55 - transmits two characters and checks txemt and txrdy for zero.
Test 56 - detects the character at the receiver and checks that txemt and txrdy
have been set to one.
Hardware Tested: The nonerror bits of the UART Status register are tested.
Data Returned: Pattern OxkOOOOOsr is returned, where sr equals the failing Status register value.
The variable k is 1 if RCVRDY experiences a time-out error or 2 if XMTRDY
experiences a time-out error.
Notes: None
Test Numbers:
Function:
Procedure:
57 and 58
These tests check bits, other than Error bits, of the Status register on the B side.
Test 57 - transmits two characters and checks txemt and txrdy for zero.
Test 58 - detects the character at the receiver and checks that txemt and txrdy
have been set to one.
Hardware Tested: The non error bits of the UART Status register are tested.
Data Returned: Pattern OxkOOOOOsr is returned, where sr equals the failing Status register value.
The variable k equals 1 if RCVRDY experiences a time-out error or 2 if
XMTRDY experiences a time-out error.
Notes: None
SYSTEM BOARD DIAGNOSTICS 3-43