JPH0331945A - Dynamic memory access system changing circuit - Google Patents

Abstract

PURPOSE:To reduce the lowering of a memory access hit ratio due to the non- coincidence of a program and a memory access system by dynamically switching the memory access system. CONSTITUTION:Memory access circuits 11 and 12 always see an address bus 16, output control signals a and b and outputs a hit condition as hit condition signals c and d by a hit check circuit inside. A memory access hit check circuit 13 switches a multiplexer 14 when the memory access circuit at a standby side is in the hit condition after the hit condition of the memory access circuit at a side to be selected at present in the memory access circuits 11 and 12 is deteriorated. Since the control signal of the memory access circuit in the hit condition is outputted, the memory access system is dynamically switched. Thus, the lowering of the memory access hit ratio due to the non-coincidence of the program and memory access system is reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to memory access control, and particularly to improving memory access hits.

[Conventional technology]

Conventionally, as the dynamic memory control methods in information processing devices have become faster, the interleaving method, dynamic memory/page mode method, and
There was a dynamic memory page mode interleaving method.

[Problem to be solved by the invention]

Each of the conventional memory access methods described above has different memory access hit characteristics, and when a memory access circuit is configured using a single method, memory accesses that are possible using other methods may differ depending on the memory access characteristics of the program being executed. There was a problem in that it was not possible to rescue humans.

[Means to solve the problem]

In order to solve these problems, the present invention includes a plurality of memory access circuits, a memory access hit check circuit that checks the access hit status of each memory access circuit, and a multiplexer that switches the memory access circuit depending on the hit status. , each memory access circuit has a different memory access method for the same memory.

[Effect]

In the dynamic memory access method changing circuit according to the present invention, memory access methods are dynamically switched.

〔Example〕

Next, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a system diagram showing an embodiment of a dynamic memory access method changing circuit according to the present invention. In the figure, a dynamic memory access method changing circuit 10 includes an interleave method memory access circuit 11 that looks at the address bus and outputs a memory control signal a, and a dynamic memory access circuit 11 that looks at the address bus and outputs a memory control signal a. A mode-based memory access circuit 12, a memory access hit check circuit 13 which receives and receives the hit state signals c and d from the hit check circuits in the memory access circuits 11 and 12, and determines which one is more efficient; A multiplexer 1 that switches the memory control signal to a or b based on the judgment signal e from the check circuit 13 and outputs it as a memory access signal f.
4. 15 is a memory.

Memory access circuits 11 and 12 always use address bus 1.
6 and outputs control signals a and b, and an internal hit check circuit detects the hit state by outputting hit state signals c and
Output as d. The memory access hit check circuit 13 switches the multiplexer 14 when the currently selected memory access circuit among the memory access circuits 11.12 is in a hit state and the standby memory access circuit is in a hit state. , outputs a control signal for the memory access circuit in the hit state.

In the above embodiment, the number of memory access circuits is two, but the number may be increased as necessary.

〔Effect of the invention〕

As explained above, the present invention has a plurality of memory access circuits for the same memory, each memory access circuit has a different memory access method, and by monitoring the hit state of each memory access circuit, The memory access method can be dynamically switched, which has the effect of reducing the decrease in memory access hit rate due to mismatch between the program and the memory access method.

[Brief explanation of drawings]

The figure is a system diagram showing an embodiment of a dynamic memory access method changing circuit according to the present invention. 10... Dynamic memory access method change circuit, 11...
・Interleave type memory access circuit, 12... Dyna ξ block memory page mode type memory access circuit, 13... Memory access hit check circuit, 14
...Multiplexer, 15...Memory, 16...
access bus.

Claims (1)

[Claims] The memory access circuit includes a plurality of memory access circuits, a memory access hit check circuit that checks the access hit status of each memory access circuit, and a multiplexer that switches the memory access circuit depending on the hit status, and each of the memory access circuits performs one operation on the same memory. A dynamic memory access method changing circuit characterized in that the circuit has different memory access methods.