EP0260433A2
Expired / Lapsed
EP
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Multi-address space control method
Assignee: Hitachi Ltd
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Filing: 1987-08-11
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Granted: —
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Expires: 2007-08-11
Abstract
Abstract A multi-address space control for use in an information processing system includes accessing a plurality of address spaces (19, 22) produced by different address translation tables based on a selection command (7) for a plurality of leading address registers (5, 6), and comparing (12) a program status word (PSW) key (P k , 1) with a main storage key (M k , 11) in a main storage to protect the main storage. The multi-address space control between different address spaces includes a PSW key register for holding the program status work key, a work access key register (2, W k ) capable of arbitrarily designating an access key in accordance with a data transfer instruction, access means for allowing an access to the main storage irrespective of the value of a main storage key (M k ) when the value of the key selected by a selector (3) as an access key from the work access key register and the PSW key register is a predetermined value (K=0), and setting means for accessing the different address spaces by changing-over the plurality of leading address registers and the work access key register and PSW register, detecting an access exception, and setting the predetermined value in the work access key register to judge the work access key as an access key if an access exception is not detected.
Inventors
- 👤 Mari Ara
- 👤 Hideo Sawamoto
- 👤 Kaname Imai
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-25 00:42
CPC Classifications
G; G06; G06F; G06F12/00; G06F12/14; G06F12/1458; G06F12/1466; G06F12/1475
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
215 words
An information processing method including accessing a plurality of address spaces (19, 22) produced by different address translation tables (9) based on a selection command (7) for a plurality of leading address registers (5, 6), and comparing (12) a program status word (PSW) key (P k , 1) with a main storage key (M k , 11) to thereby protect a main memory, comprising, in a data transfer between different access spaces, the stpes of: (a) setting a work access key (W k ) capable of being designated in accordance with an instruction to be executed, independently from said program status word key; (b) selecting as an access key (K) on the side of a central processing unit one of said program status word (PSW) key (P k ) and said work access key (W k ); (c) if the selected access key is at a predetermined value (K=0), allowing an access to said main storage irrespective of said main storage key value; and (d) accessing different address spaces by changing said plurality of leading address registers, PSW key (P k ) and word access key (W k ), detecting an access exception, and if an access exception is not detected, setting said predetermined value (K=0) as an access key in said work access key.
Claim 2
Dependent Claim
215 words
An information processing method including accessing a plurality of address spaces (19, 22) produced by different address translation tables (9) based on a selection command (7) for a plurality of leading address registers (5, 6), and comparing (12) a program status word (PSW) key (P k , 1) with a main storage key (M k , 11) to thereby protect a main memory, comprising, in a data transfer between different access spaces, the stpes of: (a) setting a work access key (W k ) capable of being designated in accordance with an instruction to be executed, independently from said program status word key; (b) selecting as an access key (K) on the side of a central processing unit one of said program status word (PSW) key (P k ) and said work access key (W k ); (c) if the selected access key is at a predetermined value (K=0), allowing an access to said main storage irrespective of said main storage key value; and (d) accessing different address spaces by changing said plurality of leading address registers, PSW key (P k ) and word access key (W k ), detecting an access exception, and if an access exception is not detected, setting said predetermined value (K=0) as an access key in said work access key.
Claim 3
Dependent Claim
37 words
A method according to claim 1, wherein each of said steps is executed under control of microprograms, said steps constituting a pre-testing (rehearsal) for setting an access key to be prepared on the central processing unit side.
Claim 4
Dependent Claim
25 words
A method according to claim 1, wherein said access exception includes translation specification exception, segment translation exception, page translation exception, addressing exception, and protection exception.
Claim 5
Dependent Claim
21 words
A method according to claim 1, wherein said step (c) includes a step of inhibiting actual accessing to said main storage.
Claim 6
Dependent Claim
38 words
A method according to claim 2, wherein said step (d) includes a store rehearsal for an address space to which a data is transferred and a fetch rehearsal for an address space from which a data is transferred.
Claim 7
Dependent Claim
229 words
An information processing system wherein a plurality of address spaces (19, 22) produced by different address translation tables based on a selection command for a plurality of leading address registers (5, 6) are accessed, and a program status word key (P k ) and a storage key (M k ) are compared to protect a main storage, having a multi-address space control system comprising: a first key register (1) for holding said program status word key; a second key register (2) for holding a work access key variably designated in accordance with an instruction to be executed; a key selector (3) for selecting said first and second key registers; judging means (4) coupled to the output of said key selector (3) for judging whether the value of key selected from said first and second key registers is a predetermined value (K=0), and enabling an access to said main storage irrespective of the value of said storage key if said selected key value is equal to said predetermined value; an means (12, 16, 4, 3, 2) for accessing different address spaces by changing said plurality of leading address registers, and said first and second key registers, detecting an access exception, and setting, if an access exception is not detected, said predetermined value in said second key register as an access key for use in transferring data between different address spaces.
Claim 8
Dependent Claim
229 words
An information processing system wherein a plurality of address spaces (19, 22) produced by different address translation tables based on a selection command for a plurality of leading address registers (5, 6) are accessed, and a program status word key (P k ) and a storage key (M k ) are compared to protect a main storage, having a multi-address space control system comprising: a first key register (1) for holding said program status word key; a second key register (2) for holding a work access key variably designated in accordance with an instruction to be executed; a key selector (3) for selecting said first and second key registers; judging means (4) coupled to the output of said key selector (3) for judging whether the value of key selected from said first and second key registers is a predetermined value (K=0), and enabling an access to said main storage irrespective of the value of said storage key if said selected key value is equal to said predetermined value; an means (12, 16, 4, 3, 2) for accessing different address spaces by changing said plurality of leading address registers, and said first and second key registers, detecting an access exception, and setting, if an access exception is not detected, said predetermined value in said second key register as an access key for use in transferring data between different address spaces.
Claim 9
Dependent Claim
215 words
An information processing system for a multi-address space control wherein when a main storage is to be accessed from a central processing unit, a main storage protection is conducted by comparing an access key prepared in said central processing unit with a main storage key provided in the main storage, comprising: a first key register (1) for storing a program status word key prepared in said central processing unit; a second key register (2) for storing an access key designated in accordance with a data transfer instruction; a selector (3) for selecting one of the outputs from said first and second key registers; judging means (4) coupled to said selector for comparing a key value from a selected key register with a predetermined value, allowing an access to said main storage irrespective of said main storage key when the key value of said selected key register matches said predetermined value, and making the key value of said selected key register to be compared with said main storage key; and means including a microprogram for executing a predetermined procedure, for setting said predetermined value in said second key register as an access key for data transfer between a plurality of address spaces when a key included in a transfer instruction coincides with said main storage key.
Claim 10
Dependent Claim
215 words
An information processing system for a multi-address space control wherein when a main storage is to be accessed from a central processing unit, a main storage protection is conducted by comparing an access key prepared in said central processing unit with a main storage key provided in the main storage, comprising: a first key register (1) for storing a program status word key prepared in said central processing unit; a second key register (2) for storing an access key designated in accordance with a data transfer instruction; a selector (3) for selecting one of the outputs from said first and second key registers; judging means (4) coupled to said selector for comparing a key value from a selected key register with a predetermined value, allowing an access to said main storage irrespective of said main storage key when the key value of said selected key register matches said predetermined value, and making the key value of said selected key register to be compared with said main storage key; and means including a microprogram for executing a predetermined procedure, for setting said predetermined value in said second key register as an access key for data transfer between a plurality of address spaces when a key included in a transfer instruction coincides with said main storage key.
Claim 11
Dependent Claim
73 words
A system according to Claim 6, wherein said instruction is a data transfer instruction, one of first and second operands is fetched and stored into the other operand address, the access key (P k ) for said one of first and second operands is designated by said program status instruction and the access key (W k ) for the other of the first and second operands is designated by said data transfer instruction.
Claim 12
Dependent Claim
34 words
A system according to Claim 8, wherein said key selector (3) selects one of the outputs of said first and second key registers (1, 2) by a microprogram associated with said data transfer instruction.
Claim 13
Dependent Claim
61 words
A system according to Claim 6, wherein said first key register (1) holds an access key to detect an access exception for one of first and second operands and said second key register (2) holds a key given by a data transfer instruction as an access key to detect an access exception for the other of said first and second operands.
Claim 14
Dependent Claim
40 words
A system according to Claim 6, wherein said second key register (2) is set at a key value always available to access for transfer of first and second operands of a predetermined unit length through repetitive fetch and store operations.
References Cited (Backward Citations)
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