JPH04140861A - Address converting system - Google Patents

Abstract

PURPOSE:To efficiently execute the address conversion by a simple hardware by storing a segment descriptor obtained in an address conversion process in a segment descriptor storage means of every physical channel. CONSTITUTION:In order to index the next table, main storage information obtained therein becomes an input of a new address operation, a fetch of an address convertion table is repeated successively, a physical address corresponding to a logical address given finally is generated, and it is stored in a physical address store register 5. In the course of a series of address converting operations thereof, in the case a segment descriptor is fetched, the descriptor concerned is stored in an address conversion table storage register 3, and simultaneously, its store in a segment descriptor storage buffer 1 corresponding to the physical channel is also executed. Unless segment switching is generated on the physical channel by this segment descriptor storage buffer 1, the registered segment descriptor is referred to, and the address converting operation is executed by the segment descriptor.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to an address conversion method, particularly an address conversion method for an input/output processing device that accesses main memory while sequentially converting logical addresses to physical addresses. [Prior Art] Conventionally, in an input/output processing device, an address conversion operation for converting a logical address into a physical address first divides a segment, which is a unit of logical address space, into pages, which are a unit of management of real memory, and divides both segments into pages. The physical address was calculated by continuously referencing the segment table display words, segment descriptors, and page descriptors representing correspondence/relationships based on the logical address. Furthermore, in order to reduce the time required for this address conversion, conversion pairs have been implemented using large-scale and high-speed hardware.

[Problem to be solved by the invention]

In the address conversion method in the conventional input/output processing device described above, when converting a logical address to a physical address, it is necessary to index the segment table display word, segment descriptor, and page descriptor prepared in main memory. The disadvantage is that it takes time.

In addition, in order to reduce the time required for address translation, there is a method in which an address translation pair is provided, in which the physical address corresponding to the logical address is registered in advance, and then the physical address is obtained without the need for translation processing. However, there is a drawback that the address translation pair requires large-scale and high-speed hardware.

[Means for Solving the Problems] The address translation method of the present invention includes: an address space made up of a plurality of segments each made up of a plurality of pages; and a page made up of a page descriptor that holds control information for the page. a main storage device that stores a segment table composed of a table and a segment descriptor that holds control information of the segment; and a segment table display word that holds information about the segment table; In an address conversion method in a data processing device, the data processing device has an input/output processing device that performs main memory access while indexing the segment table display word, the segment descriptor, and the page descriptor from a logical address and converting the same into a physical address, The input/output processing device has segment descriptor storage means for registering the segment descriptor obtained in the process of converting a logical address into a physical address for each physical channel, and the input/output processing device on a certain physical channel In the case of accessing a segment indicated by a stored segment descriptor, an address conversion is performed based on the segment descriptor registered in the segment descriptor storage means to obtain a physical address.

〔Example〕

Next, the present invention will be explained with reference to the drawings.

FIG. 1 is a block diagram showing the configuration of an embodiment of the present invention. In FIG. 1, this embodiment has a segment descriptor storage buffer 1.0 that stores segment descriptors corresponding to physical channels. Logical address storage register 2. Address conversion table storage register 3 in which various address conversion tables referred to during address conversion are stored. Address calculation circuit 4, physical address storage register 5. The common bus consists of a physical channel number 7 indicating a storage location in a 6° segment descriptor storage buffer and a software noise error detection circuit 8 in address conversion.

In the address conversion operation, first, the logical address that is the basis of address conversion is placed in the logical address storage register 2, and the address space display word is placed in the address conversion table storage register 3.
A desired physical address pointing to the segment table display word array is calculated by the address arithmetic circuit 4 and stored in the physical address storage register 5.

Main memory access is performed using this physical address, and the segment table display word is retrieved. The segment table display word extracted here is stored in the address conversion table storage register 3 via the common bus 6 in order to extract the segment descriptor to be indexed next, and the desired physical address of the segment table is stored in the same manner. is obtained and the segment descriptor is retrieved from main memory. Thereafter, a page table physical address is generated using the segment descriptor, and page descriptor retrieval continues.

In this way, for the next table index, the main memory information obtained there is used as a new input for address calculation, and sequentially,
The extraction of the address conversion table is repeated, and finally a physical address corresponding to the given logical address is generated and stored in the physical address storage register 5.

During this series of address translation operations, when a segment descriptor is taken out, the descriptor is stored in the address translation table storage register 3 and at the same time, storage in the segment descriptor storage buffer 1 corresponding to the physical channel is also executed. Ru. With this segment descriptor storage buffer 1, unless segment switching occurs on the physical channel, the registered segment descriptor is referenced and address conversion is performed from the segment descriptor.

The above operations are controlled by a microprogram. FIG. 2 is a diagram showing the relationship between logical addresses and various address translation tables in address translation.

〔Effect of the invention〕

As explained above, in an input/output processing device that performs main memory access while sequentially converting logical addresses into physical addresses, segment descriptors obtained in the address conversion process are stored as segment descriptors for each physical channel. By storing the information in the means, there is an effect that address translation can be efficiently performed using simple hardware.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the configuration of an embodiment of the present invention, and FIG. 2 is a diagram showing the relationship between logical addresses and various address conversion tables in address conversion. 1... Segment descriptor storage buffer, 2... Logical address storage register, 3... Address conversion table storage register, 4... Address calculation circuit, 5... Physical address storage register, 6... Common bus , 7... Physical channel number, 8... Software error detection circuit.

Claims (1)

[Scope of Claims] An address space consisting of a plurality of segments each consisting of a plurality of pages, a page table consisting of a page descriptor holding control information of the page, and a segment description holding control information of the segment. a main storage device that stores a segment table composed of children; a segment table display word that holds information regarding the segment table; and a main storage device that stores the segment table display word and the segment descriptor stored on the main storage device; In an address conversion method in a data processing device, the input/output processing device has an input/output processing device that performs main memory access while indexing the page descriptor from a logical address and converting it to a physical address, wherein the input/output processing device converts a logical address to a physical address. The segment descriptor storage means registers the segment descriptor obtained in the conversion process for each physical channel, and input/output operations on a certain physical channel access the segment indicated by the stored segment descriptor. In this case, the address conversion method is characterized in that the address conversion is performed based on the segment descriptor registered in the segment descriptor storage means to obtain a physical address.