Page of GA22-7000-4 Revised September 1, 1975
By TNL: GN22-0498
device
addressing,I/O 192
validity flag 241
description 18
end(I/O unit status condition) 232
error,I/O 197
general information 186
not operational(I/O system state) 193
working% system state) 193 (sa also I/O devices and control units) DIAGNOSE instruction 103 digit, decimal 147
digit selector in editing150 direct-control facility 46
disabling, enabling interruptions70 displacement (in operand designation) 20 display-and-enter controls 245
DIVIDE (DDR, DD, DER, DE) instruction 163
DIVIDE (DR, D) instruction 128
example 296
DIVIDE DECIMAL (DP) instruction 149
example306 doubleword (definition) 14
doubleword-concurrent fetch 27
dynamic address translation 57
addresses translated 62
addressing exception during 61,68
control 58
control register0 58
control register 1 59
exceptions 68, 81
page-translation exception 79, 62
segment-translation exception 79,61
translation-specification exception 79,62
formats, summary 68
page invalid bit60 page size 59
page table
address60 entry 60 entry fetch sequence 24
length60 lookup '61 process 60 segment invalid bit 60 segment size 59
segment table
address 59
entry 59
entry fetch sequence 24
length 59
lookup 61
states of translation-table entries 65
table entries
active 66
attached 65
valid 65
tables 59
modification of 66
translation lookaside buffer 65
EBClDIC chart (see Appendix H)
EDIT AND MARK (EDMK) instruction 152
example307 318 System/370 Principles of Operation EDIT (ED) instruction 150 example 306 emergency-pull switch 245
emergency signal
external interruption 87
order 97
enable-system-clear key 245
enabling anddisabUng interruptions 70 ending of instruction execution, methods of 74
equipment check (sense data)220 status bit 99
error
program, handling of 75
state of time-of-day clock 46
storage
corrected bit180 key in storage 180 uncorrected bit 180 error checking and correction (ECC), redundancy correction 172
event mask for program event recording40 events, interruption causing 80 exception conditions
during decimal operations 149
during EXECUTE operations 129
during fixed-point operations 116
during floating-point operations 161
exceptions associated withPSW 35
excess-64 binary notation 157EXCLUSIVE OR (XR, X, XI,XC) instruction 128
example 297
EXECUTE (EX) instruction 129
example 298
exceptions during execution 129
executeexceptioJ;l 76
execution, program 19
exigent machine-check interruption conditions
definition of 175
handling of (interruption action) 175, 177
explicit (address) translation60 exponent
in a floating-point number 157
overflow exception 78
underflow exception 79
extended control mode (EC) 32PSW format 34
extended-floating-point number 158
extended logout (see machine-check extended logout)
extended logout pointer,I/O 240 external-call
external interruption 87
order 97
pending, status bit 99
external damage, machine-check interruption condition 179, 175
report mask 182
external interruption 84
clock comparator 87
CPU timer 88
emergency signal 87
external call 88
external signal 86
identification in main storage90 interrupt key 86
interval timer 86
malfunction alert 86
By TNL: GN22-0498
device
addressing,
validity flag 241
description 18
end
error,
general information 186
not operational
working
digit selector in editing
disabling, enabling interruptions
DIVIDE (DDR, DD, DER, DE) instruction 163
DIVIDE (DR, D) instruction 128
example 296
DIVIDE DECIMAL (DP) instruction 149
example
doubleword-concurrent fetch 27
dynamic address translation 57
addresses translated 62
addressing exception during 61,68
control 58
control register
control register 1 59
exceptions 68, 81
page-translation exception 79, 62
segment-translation exception 79,61
translation-specification exception 79,62
formats, summary 68
page invalid bit
page table
address
length
segment table
address 59
entry 59
entry fetch sequence 24
length 59
lookup 61
states of translation-table entries 65
table entries
active 66
attached 65
valid 65
tables 59
modification of 66
translation lookaside buffer 65
EBClDIC chart (see Appendix H)
EDIT AND MARK (EDMK) instruction 152
example
emergency signal
external interruption 87
order 97
enable-system-clear key 245
enabling and
equipment check (sense data)
error
program, handling of 75
state of time-of-day clock 46
storage
corrected bit
event mask for program event recording
during decimal operations 149
during EXECUTE operations 129
during fixed-point operations 116
during floating-point operations 161
exceptions associated withPSW 35
excess-64 binary notation 157
example 297
EXECUTE (EX) instruction 129
example 298
exceptions during execution 129
execute
execution, program 19
exigent machine-check interruption conditions
definition of 175
handling of (interruption action) 175, 177
explicit (address) translation
in a floating-point number 157
overflow exception 78
underflow exception 79
extended control mode (EC) 32
extended-floating-point number 158
extended logout (see machine-check extended logout)
extended logout pointer,
external interruption 87
order 97
pending, status bit 99
external damage, machine-check interruption condition 179, 175
report mask 182
external interruption 84
clock comparator 87
CPU timer 88
emergency signal 87
external call 88
external signal 86
identification in main storage
interval timer 86
malfunction alert 86