JPH0248735A - High speed overlay system for program - Google Patents

Abstract

PURPOSE:To easily execute program overlay at a high speed by previously loading programs on plural bank memories and transferring only a necessary part between the bank memories by means of direct memory access. CONSTITUTION:The bank memories exist in the center part of a main storage memory, and there are six banks 1-6. CPU can access to only non-bank parts 7 and 8 and the bank memory 1 and it can access to the memory banks 2-6 by the switching of the banks. Namely, the program required at the time of executing the program are transferred to the bank 1 from the banks 2-6 after all the programs are loaded as an initial processing. Thus, program overlay can be executed at a considerably higher speed compared to overlay from an auxiliary storage device.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a system for performing program overlay, and more particularly to a system in which the entire program must interface and which must operate at high speed.

(Prior Art) Conventionally, when a program cannot be stored in the main memory as described above, the first program is overlayed from the auxiliary memory.
A method is known in which access is performed by one method or a second method in which a program is loaded in advance into a plurality of punctures and the punctures are switched.

(Problems to be solved by the invention) The first conventional method described above requires input/output processing to read the program from an auxiliary storage device such as a magnetic disk, and it takes a long time to complete the overlay. There is a drawback. On the other hand, in the second conventional method, each bank memory is independent, and there is a drawback in that it is not possible to operate while maintaining an interface between four groups of different bank memories.

An object of the present invention is to eliminate the above-mentioned drawbacks by loading a program into multiple bank memories in advance and transferring only the necessary portions between the bank memories using direct memory access, thereby making it possible to easily perform program overlay. The object of the present invention is to provide a high-speed overlay method for structured programs.

(Tth Means for Solving the Problems) A high-speed program overlay method according to the present invention includes first to Nth bank memories arranged in order to store programs, and a non-bank part, In addition to the programs in the first bank memory, programs from the second and subsequent bank memories can be transferred to and accessed from the first bank memory.

(Example) Next, one embodiment of the present invention will be explained with reference to the drawings.

FIG. 1 is an explanatory diagram showing an embodiment of a high-speed program overlay method according to the present invention.

In this embodiment, the central part of the main memory is a bank memory, and there are six banks 5.1 to 6. CPU
Although only the non-bank portions 7 and 8 and the bank memory 1 can be accessed independently, by switching banks, it is also possible to access mesori banks 2 to 6.

After loading all programs as initial processing.

A memory program required when executing a program is transferred from banks 2 to 6 to bank 1.

In the embodiment of FIG. 2, (a) shows the initial state.

In the initial state shown in FIG. 2(1), the system operates only with the programs in bank 1. Thereafter, as shown in FIG. 2, part of the program is transferred from bank 2 to bank 1, and the system operates with the contents of both banks 1 and 2.

In Figures 2(C) and (d), banks 3 and 4, respectively.
A portion of the contents of is transferred to bank 1.

In this way, only the necessary parts of the contents of different bank memories can be collected in bank 1.
It is possible for the system to operate with banks 1-6 interfacing with each other.

(Effects of the Invention) As explained above, the present invention provides 5. direct memory transfer of a program from a bank memory. Program overlays can be performed much faster than overlays from auxiliary storage.

However, since the contents of the bank memory are divided and only a portion is transferred, it is possible to freely interface between each program.

Additionally, the program allocation method is the same as the overlay method from the auxiliary storage device, so if the program cannot be stored in the bank memory, programs that do not need to be accelerated can be stored in the auxiliary storage device. This has the effect of allowing normal overlay to be performed.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram showing an embodiment of a high-speed program overlay method according to the present invention. FIG. 2 is an explanatory diagram showing the operation of the program shown in FIG. 1 in a high-speed overlay method. 1 to 6... Bank memory 7.8... Non-bank patent applicant NEC Corporation Same as above Agent of NEC Telecom System Co., Ltd.
Patent Attorney Hisashi Inoro 7 Figure 22 (a) (b) (C) (d)

Claims (1)

[Claims] The first to Nth bank memories are arranged in order to store programs, and a non-bank part is provided.
1. A high-speed program overlay system, characterized in that, in addition to the program in the bank memory, programs from the second and subsequent bank memories can be transferred to and accessed from the first bank memory.