JPS59163620A - Memory device - Google Patents

Abstract

PURPOSE:To perform the initialization only with a volatile memory for the initialization of a memory device obtained from a combination of the volatile and nonvolatile memory modules, by transmitting an inhibition signal to the nonvolatile memory module to discontinue the writing and reading of data. CONSTITUTION:An inhibition signal is transmitted to a control line 102 from a control module 10 prior to an initialization. Then nonvolatile memory modules 30 and 31 discontinue their reading/writing actions with said inhibition signal. The module 10 writes the zero value to memory modules 20, 21, 30 and 31 respectively while it is delivering the inhibition signal. In this case, however, the writing is actually carried out only to the modules 20 and 21. Thus the module 10 discontinue the generation of the inhibition signal after the initialization is through with the volatile module. As a result, a memory device containing both volatile and nonvolatile memories can have a smooth actuation in case the power is supplied again after the external power supply is stopped.

Description

[Detailed Description of the Invention] 1) Description of the technical field to which the invention pertains The present invention relates to a memory device, and particularly to a memory device that controls initialization operations when volatile memory and nonvolatile memory coexist. The present invention relates to memory devices.

(2) Description of the Prior Art Semiconductor memories are often used as memory elements from which data can be read and written. Generally, this type of semiconductor memory is a volatile memory whose stored contents are lost when the power supply is stopped, and the stored contents are undefined when the power supply is resumed. Therefore, it is necessary to initialize the stored contents after power supply is started, and therefore, a method of writing a value of zero to all memories is generally used. On the other hand, non-volatile memory is used to ensure that the stored contents are not lost even if the power supply is stopped, but the stored contents of this non-volatile memory cannot be initialized after the power supply is started. Can not.

Generally, non-volatile memory is more expensive than volatile memory, so a method is used in which non-volatile memory and volatile memory are used together. In a memory device that combines volatile memory and non-volatile memory, it is necessary to initialize only the volatile memory, but if the capacity of the volatile memory is not determined in advance, it is necessary to initialize the non-volatile memory as well. Initialization may be executed.

(3) Detailed Description of the Invention An object of the present invention is to initialize the volatile memory without setting the capacity of the volatile memory to a fixed capacity in a memory device in which volatile memory and non-volatile memory are mixed. An object of the present invention is to provide a memory device having the following features.

(4) Structure of the Invention The present invention has a plurality of memory modules capable of writing and reading data, and a control module connected to the plurality of memory modules, and converts the plurality of memory modules into volatile memory. The control module is composed of a combination of a module and a non-volatile memory module, and when power supply starts, the control module generates a prohibition signal to stop writing and reading data in the non-volatile memory module, and also outputs initial data to the plurality of memory modules. The memory device is characterized in that the "inhibit" signal is sent to the non-volatile memory module during the writing period of the initial data, and only the volatile memory module is initialized.

(5) Detailed Description of the Invention Next, embodiments of the invention will be described in detail with reference to the drawings.

The figure is a block diagram showing the configuration of an embodiment of the present invention.

In FIG. 1, a plurality of memory modules 20, 2
The memory modules 1 , 30 , 31 have a certain storage capacity and can write and read data, and the memory modules 20 , 21 , 30 , 31 are connected to the control module 10 by an information transfer path 101 . .

The control module 10 connects the R 20 to the information transfer path 101.
, 21 , 30 , and 31 . At this time, the information transfer path 101 also transfers data. That is, in a write operation, data is sent from the fi control module 10 to the information transfer path 101, and the memory module whose address is specified by the address information transferred by the information transfer path 101 receives the data. In a read operation, the addressed memory module sends data to the information transfer path 101 and the control module 10 receives the data. In reading and writing such data, the memory module 20,
21, 30, and 31 can be treated as being different only in their storage addresses. The above description is based on the control module 10, memory modules 20, 21,
This relates to the operation when power is supplied to 30 and 31.

Next, a case where power supply is stopped and then restarted will be described. Semiconductor memories, which are often used as readable and writable storage elements, are volatile memories whose stored contents are lost when power supply is stopped. A magnetic core (non-volatile memory) is a storage element whose stored contents are not lost even if the supply of power is stopped and can be read and written. In addition, by adding a battery circuit, the power supply to the storage element does not stop even if the external power supply stops, so that volatile memory can be treated as non-volatile memory. Can be done. In a volatile memory, the stored contents are generally undefined when power supply is started. Therefore, initialization is generally performed by writing a value of zero. Here, the memory modules 20 and 21 are assumed to be volatile memory modules using volatile memory, and the memory modules 30 and 31 are assumed to be nonvolatile memory modules using nonvolatile memory. When the power supply to the entire memory device shown in FIG. 1 is stopped and then restarted, it is necessary to initialize the volatile memory modules 20 and 21. Therefore, when the power supply is started, the control module 1o sequentially writes a value of zero to each address of the memory modules 20 and 21.

If the address of a volatile memory module is fixed, a value of zero can be written only to the fixed address. However, if the addresses of volatile memory modules are not fixed and you want to use any combination of volatile and non-volatile memory modules, then may be initialized.

Therefore, in the present invention, in order to initialize only the volatile memory module, the control module 10 sends an inhibit signal to the control line 102 prior to the initialization operation. The non-volatile memory modules 30 and 31 are connected to the control line 10
When a prohibition signal is sent by 2, reading and writing operations are stopped. Such read and write operations can be easily stopped by gating the read and write control lines. The control module 10 continues to output the prohibition signal and the memory modules 20 , 21 , :
A zero value is written to 30 and 31, but the actual writing is to volatile memory module 2.
0, 21 only. After the initialization of the volatile memory module is completed in this way, the control module 1
0 stops generation of the inhibit signal. When the inhibition signal disappears, the memory modules 30, 31 can read data,
Since it is writable, the stored contents will not be lost.

(6) Detailed Description of the Invention As explained above, the present invention allows a control module to send a prohibition signal to a non-volatile memory module when initializing the memory module to write data in the memory module. Since reading is stopped and initialization is performed, it is possible to initialize only the volatile memory module in a memory device that is a combination of a volatile memory module and a non-volatile memory module. be.

[Brief explanation of the drawing]

The figure is a block diagram showing the configuration of an embodiment according to the present invention. 10...Control module, 20.21...Volatile memory module, 30.31...Nonvolatile memory module Patent applicant NEC Corporation

Claims (1)

[Claims] (1) A volatile memory module that has multiple memory modules that can write and read data and a control module that is connected to the multiple memory modules, and whose stored contents are lost when the power is turned off, and the power state The plurality of memory modules are configured in combination with a nonvolatile memory module whose memory contents are retained regardless of the power supply, and the prohibition signal for stopping data writing and reading in the nonvolatile memory module is provided when power supply is started. generated by a control module and requests the plurality of memory modules to write initial data, and after the initial data writing is completed, the generation of the prohibition signal is stopped to initialize only the volatile memory module. A memory device characterized by: