JPH04134786A - Memory address circuit - Google Patents

Abstract

PURPOSE:To reduce the number of program steps by adding an increment function to the address circuit of a memory. CONSTITUTION:A microprocessor 1 transfers the address of a memory 2 to an addressing means 3 which addresses the memory 2, and transfers the data to the memory 2. After this operation, the address means 3 increases the address of the memory 2, and when the microprocessor transfers the data to the memory 2 again, this time, the address of the memory is increased for an amount of one address from before. Thus, the program for setting the address of the memory 2 becomes unnecessary, and the number of the program step is reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a memory address circuit, and particularly to a memory address circuit that has a large amount of memory and has the function of frequently repeating memory access.

[Conventional technology]

Conventionally, microcomputers having this type of memory access mechanism have designated each memory address one by one when accessing memory. In particular, when using a 4-bit microcomputer and accessing memory continuously from a lower address to an upper address, the memory address is incremented by 4 bits (+1 addition), and if the memory address exceeds 4 bits, If so, increment the lower 4 bits and determine whether there is an up digit, then increment the upper 4 bits and determine whether there is an up digit, then increment the upper 4 bits. The memory address was calculated by repeating increments of 4 bits at a time.

[Problem to be solved by the invention]

The above-described conventional memory address means has the disadvantage that if a large amount of memory is used and the memory is accessed frequently, the address operation takes a number of program steps and is difficult to program.

SUMMARY OF THE INVENTION An object of the present invention is to provide a memory address circuit which solves the above-mentioned drawbacks, requires fewer program steps, and allows easy programming.

[Means to solve the problem]

The configuration of the memory addressing circuit of the present invention includes a memory accessed by a microprocessor, and an addressing means for addressing the memory accessed by the microprocessor, and the addressing means is configured to enable the microprocessor to access the memory. It is characterized by having a function of incrementing the address of the memory when accessed.

〔Example〕

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

FIG. 1 is a block diagram of a memory address circuit according to a first embodiment of the present invention.

In FIG. 1, in this embodiment, the microprocessor 1 first transfers the address of the memory 2 to the address means 3 for addressing the memory 2, and then transfers data to the memory 2. After this operation, the address means 3 increments the address of the memory 2. When microprocessor l transfers the memory 2 hetator again, the address of memory 2 is incremented by one address from the previous time. By repeating these operations and accessing the memory 2, a program can be created without being aware of the address of the memory 2.

Conversely, when data is transferred from the memory 2, a similar address operation can be performed.

FIG. 2 is a block diagram showing only the addressing means of the memory address circuit according to the second embodiment of the present invention. In FIG. 2, as a second embodiment, two addresses, a start address 4 and a stop address, of the memory 2 can be set in the address means 3 of FIG. 1 by the microprocessor 1, and Data is transferred from the start address 4 of the memory 2, and the start address 4 is sequentially incremented by the incrementer 5. When the first set stop address is reached, incrementing is prohibited and subsequent addresses cannot be accessed. By doing so, it is possible to prevent memory data from being destroyed due to program malfunction.

In FIG. 3, it is a block diagram showing only the addressing means of the memory address circuit of the third embodiment of the present invention.

In FIG. 3, in this embodiment, an address comparison circuit 9 to which a start address 4 and a stop address 8 are input is further provided in the circuit of FIG. be done.

In a memory with a long data length or a memory with a fixed length, the number of incrementations is determined in advance, and incrementing is prohibited when the number of increments is exceeded, thereby preventing memory data from being destroyed due to malfunction of the block.

〔Effect of the invention〕

As explained above, the present invention is particularly useful for microcomputers having a large amount of memory, by adding an address circuit dedicated to the memory and adding an increment function to that address circuit. For example, if you want to read an external asynchronous signal and store it in memory, consider the flow of first setting the memory address, then reading the external signal, and then storing the external signal in memory. Since it is not necessary to program a set of memory addresses, the number of program steps can be reduced, external signals can be read at high speed, and necessary memory data can be prevented from being destroyed.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the memory address circuit of the second embodiment of the present invention, FIG. 2 is a block diagram showing only the addressing means of the second embodiment of the present invention, and FIG. FIG. 7 is a block diagram showing only address means in a third embodiment. 1...Microprocessor, 2...Memory, 3...Address means, 4...Start address, 5...Incrementer, 8・
...Stop address, 9...Address comparison circuit. Agent Patent Attorney Susumu Uchihara Memory Address

Claims (2)

[Claims] (1) A memory accessed by a microprocessor, and address means for addressing the memory accessed by the microprocessor, the address means incrementing the address of the memory when the microprocessor accesses the memory. A memory address circuit characterized in that it has a function to. (2) The function to increment the memory address is
2. The memory address circuit according to claim 1, having a function of prohibiting incrementing when a specific address is exceeded.