IBM System/370 . 9
General-Purpose Design . 9
Compatibility. 10 System Program . 10 Availability 11 System Organization. 13
Main Storage . 13
Information Formats 14
Addressing 14
Information Positioning 15
Central Processing Unit. 15
General Registers 16
Floating-Point Registers 16
Control Registers 16
Input and Output 17
Channels. 17
Input/Output Interface 17
Input/Output Devices and Control Units. 18 System Console . 18
Program Execution 19
Instructions . 19
Operands. 19
Instruction Format 20 Address Generation . 21
Program Status Word 22
Instruction Execution 22
Branching. 22
Interruptions. 22
Sequence of Storage References 23
Instruction Fetch 23
DAT Table Fetches . 24
Key-in-Storage Accesses 24 Storage-Operand References 25 Storage-Operand Consistency 26
Relation Between Operand Accesses 27
Serialization . 28 System Control 29 CPU States 30 Wait and Running States 30 Problem and Supervisor States. 30 Stopped and Operating States . 30 Control Modes 31
BC Mode. 32
EC Mode. 32 Set-System-Mask Suppression 32
Program Status Word 32
Program Status Word Format in BC Mode 33
Program Status Word Format in EC Mode 34
Exceptions Associated with the PSW . 35
Control Registers 36
Key in Storage 38
Protection 38
Protection Action 38
Accesses Protected 39
Monitoring 39
Page Revised September 1, 1975
By TNL: GN22-0498 Contents
Program-Event Recording . 39
Control Register Allocation 40 Operation. 40 Storage Area Designation 42
Program Events . 42
Indication of Events Concurrently with Other Interruption Conditions 43
Direct Control 46
Time-of-Day Clock 46
Format 46 States. 46 Setting and Inspection of Value 47
Clock Comparator 47 CPU Timer 48
In terval Timer 49
Externally Initiated Functions 50 Resets. 50 Store Status . 54
Initial Program Loading. 54
Dynamic Address Translation. 57
Logical Storage Addressing. 58
Control 58 PSW 58
Control Register 0 58
Control Register 1 59
Translation Tables 59
Segment-Table Entries 59
Page-Table Entries 60 Transla tion 60 Types of Translation 60 Translation Process . 60 Addresses Translated 62
Interlocks Between Logical and Real Storage References 63
Table Manipulation . 64
Translation-Lookaside Buffer . 64 States of Translation-Table Entries 65 Use of the Translation-Lookaside Buffer . 65
Modification of Translation Tables 66
Reference and Change Recording . 67
Address-Translation Exceptions 68 Summary of Dynamic Address Translation Formats 68
Interruptions 69
Interruption Action. 70 Source Identification 70. Enabling and Disabling . 70 Instruction-Length Code 71
Point of Interruption 74
Instruction Execution 74
Machine-Check Interruption 75
Program Interruption 75
Program Interruption Conditions 75
Recognition of Access Exceptions 80 Handling of Multiple-Program-Interruption Conditions. 83
Supervisor-Call Interruption 84
External In terruption 84
Input/Output Interruption. 88
v
Page of GA22-7000-4 Revised September 1, 1975
By TNL: GN22-0498 Restart
Priority of Interruptions
Assigned Main-Storage Locations .
Real Main Storage .
Absolute Main Storage Multipl'Ocessing . . Shared Main Storage Prefixing. . . . . CPU Signaling and Response Orde:rs . . . . .
Conditions Determining Response . TOD Clock Synchronization . CPU Address Identification Syste m-Control Instructions DIAGNOSE. . . . INSERT PSW KEY. . INSERT STORAGE KEY LOAD CONTROL . . LOADPSW .... LOAD REAL ADDRESS PURGETLB ....
READ DIRECT. . . RESET REFERENCE BIT . SET CLOCK . . . .. SET CLOCK COMPARATOR. SET CPU TIMER . . . . SET PREFIX . . . . . SET PSW KEY FROM ADDRESS. SET STORAGE KEY . SET SYSTEM MASK . . . . SIGNAL PROCESSOR. . . . STORE CLOCK COMPARATOR. STORE CONTROL. . STORE CPU ADDRESS STORE CPU ID. . STORE CPU TIMER STORE PREFIX STORE THEN AND SYSTEM MASK STORE THEN OR SYSTEM MASK WRITE DIRECT General Instructions. Data Format. . . .
Number Representation
Instructions. . . .
vi
ADD .....
ADD HALFWORD .
ADD LOGICAL. .
AND .....
BRANCH AND LINK
BRANCH ON CONDITION BRANCH ON COUNT. .
BRANCH ON INDEX HIGH
BRANCH ON INDEX LOW OR EQUAL COMPARE . . . . . . . COMPARE AND SWAP COMPARE DOUBLE AND SWAP COMPARE HALFWORD . . . COMPARE LOGICAL. . . . COMPARE LOGICAL CHARACTERS UNDER MASK COMPARE LOGICAL LONG . CONVERT TO BINARY . CONVERT TO DECIMAL.
DIVIDE . . . . . .
88
89 90 90 91
95
95
95
97
97
98 101 101 103 103 104 105 105 105 106 107 107 · 107 108 108 109 109 109 110 110 110 · 111 · 111 · 112
112
113
113
113
114
114
115
116
116
117
117
117 · 120 · 120 · 121 · 121 · 122 · 122 · 123 · 123
123 · 124 · 125 · 125
126
126
127
128
128 EXCLUSIVE OR EXECUTE .. INSERT CHARACTER. INSERT CHARACTERS UNDER MASK LOAD .... LOAD ADDRESS . . LOAD AND TEST. . LOAD COMPLEMENT. LOAD HALFWORD LOAD MULTIPLE . LOAD NEGATIVE. LOAD POSITIVE MONITOR CALL MOVE MOVE LONG MOVE NUMERICS . MOVE WITH OFFSET. MOVE ZONES. . . MULTIPLY. . . . MULTIPLY HALFWORD . OR ..... . PACK ..... . SET PROGRAM MASK. SHIFT LEFT DOUBLE. SHIFT LEFT DOUBLE LOGICAL SHIFT LEFT SINGLE. . . . SHIFT LEFT SINGLE LOGICAL. SHIFT RIGHT DOUBLE . . . SHIFT RIGHT DOUBLE LOGICAL . SHIFT RIGHT SINGLE SHIFT RIGHT SINGLE LOGICAL STORE . . . . . . . . STORE CHARACTER. . . . STORE CHARACTERS UNDER MASK. STORE CLOCK. . STORE HALFWORD STORE MULTIPLE SUBTRACT. . . SUBTRACT HALFWORD . SUBTRACT LOGICAL. SUPERVISOR CALL TEST AND SET. . TEST UNDER MASK TRANSLATE
TRANSLATE AND TEST . UNPACK Deci mal Instructions. Data Format. . Zoned Format . . Packed Format . .
Number Representation
Instructions .
ADD DECIMAL. . COMPARE DECIMAL .
DIVIDE DECIMAL.
EDIT ..... .
EDIT AND MARK. . MULTIPLY DECIMAL. SHIFT AND ROUND DECIMAL . SUBTRACT DECIMAL. ZERO AND ADD . . .
Floating-Point Instructions. Data Format.
Guard Digit . . . . . .
128
129 130 130 130 131
131
131
131
132
132
132
132
133
133
135
135
136
136
136
137
137
138 · 138
139
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139 140 140 140 141
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144 · 144
145
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149
149 150 152
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