IBM System/370

MACHINE INSTRUCTION FORMATS
FIRST HALFWORD SECOND HALFWDRD THIRD HALFWORD
I
I S~~~~J~ 1 ~~r~~T~~ 2 I
I I_~' I
AA I Op Code I At !ji2J I
o REG;S~E~ 112 151 I
: OPERC~~ I ~~~R~:
Axl OpCode EI X2 I B2 ! 02 I
78 1112 ISI6 1920 31
: S~~~~TJ~l S~~~~~3 ~~RRf~t~F :
Asl OpCode \~1
o 78 JJ 12 1516 1920 31
I Ib~~~~~A6E: ~~JlRR~~b ,?F :
51! OpCode tr:~
~ 78 1516 1920 31
I I ~~~:1~6 ~F I
I I~-==i
sL OpCode I 62 I ~
o I IS 16 1920 31
I OPERAND 1 OPERAND 2 OPERAND 1 I OPERAND 2
tOPCode~~
{
I LENGTH LENGTH ADDRESS OF I ADDRESS OF
55 0 78. IJl2 1516 1920 3132 3536 47
; I LENGTH ; ~~J>:f~b ~F : ~~:£~b ~F :
Ii OpCode Ff=FBT3cTill~
l 0 1~ 1516 1920 3132 3536 4'
I
CONTROL REGISTERS
CR Bit.
Name of fMkI
Aaoo:ioJted with Inlt.
0
0
Block·multiplex'g control
Block·multiplex 'g
0
1
SSM suppression control
SSM instruction
0
2
TOO clock sync control
Multiprocessing
0
5-9
rage size controi
} Dynamic addr. transl,
0
10
Unassigned (must be zero}
0
11·12
Segment size control
0
16
Malfunction alert mask
} Mu I tiprocessi ng
0
17
Emergency signal mask
0
18 Extemal call mask
0
19
TOO clock sync check mask
0
20
Clock comparator mask
Clock comparator 0
21
CPU timer mask
CPU timer 0
24 Interval timer masR
Interval timer I
25
Interrupt key mask
Interrupt key 1
26
External signal mask
External signal 1
1
0-7
Segment table length
I Dynamic addr, transl.
I
0
8-25
Segment table addf'ess
0
2
0-31
Channel masks
Channels
I
1
8
16-31
Monitor masks
Monitoring
,
0
9 0
Successful branching event mask
I
0
1 Instruction fetching event mask
0
I . 1
I
Storage alterarlOn event mask Program-event recora'g
GR alteration event mask
, 16-31
flER general register masks
0
10 8-31
PER starting address Program-event record'g
I
0
11 8-31
PE R endi ng address
Program-event record'g
0
14
0
Check'stop control
I Machine-check handling
1
1 Svnch. MCEL control 1
2 110 extended logout control
110 extended logout 0
4
Recovery report mask
) """'"~""'. """"'"
0
5
Degradation report mask
0
6
Ext. damage report mask 1
7
Warning mask
0
8
Asynch. MCEL control
0
9
Asynch. fixed log control
0
15
8-28
MCEL address Machine-check handling
512
Page 2·12