Peripheral Error Codes - NCR PC4i Service Manual

LEVEL 1 DIAGNOSTICS ERROR RETURNS
SERIAL COMMUNICATIONS ERROR TEST
Format of code:
PERIPH:01:ww
EXP DATA :xxf OBS DATA: yy
Where, ww = Detail code
xx = Optional expected data
yy = Optional observed data
NOTE: EXP DATA and OBS DATA are in reference to the
registers in error. If a register is not in
question these fields
Detail Code:
The detail code is a bit sensitive code. It is
displayed on the CRT as a hex code with bit 7 as
the MSB and bit 0 as the LSB. An "x" represents
the ''Don't Care State". The detail codes are to
c o n s t r uc t
communication failures. Block 1 codes represent
failures of the 8250 serial communications chip
or the line drivers used to transmit or receive
data from the serial (RS 232) port: To form the
e rror
diagnostics are logically
the following bit designation is used.
bits 0,1
bits 2,3
bits 4
bits 5,6
bits 7
NOTE: See Figure 5-25
definitions
5-38

PERIPHERAL ERROR CODES

Date
the error
code the detail
communications channel selected
error during transmit or receive
internal/external loop back test
control/status errors
time out or receive data error
Time
are not displayed.
code for
codes for
"or" ed. Observe that
for s t a t u s / c o n t r o l
all serial
block 1