KR19980060841U - Memory management device - Google Patents

Abstract

The present invention relates to a memory management apparatus, and more particularly, to a memory management apparatus for optimizing the use of the excess portion of the flash memory (flash memory). The memory management apparatus includes: memory means capable of reading / writing data and storing system command codes and data changed during system use; And a control means for reading the system command code stored in the memory means to drive the system and designating a storage area of data input to the memory means.

Description

Memory management device

1 is a block diagram showing a memory management apparatus according to the prior art.

2 is a block diagram showing a memory management apparatus according to the present invention.

3 is a detailed circuit diagram of a memory management apparatus according to the present invention.

4 is an operation flowchart of a memory management apparatus according to the present invention.

* Description of the symbols for the main parts of the drawings *

1,11: Controller 2: EPROM

3: SRAM4: battery

5: EEPROM6,14: Address / Data Bus

12: memory management circuit 13: flash memory

AND: endgate

The present invention relates to a memory management apparatus, and more particularly, to a memory management apparatus for optimizing the use of the excess portion of the flash memory (flash memory).

Almost all electronic devices are equipped with a memory for storing software required for driving the device. The data stored in the memory stores general data about the device, such as software for driving the device and data according to the usage of the device.

For example, a memory provided in an electronic device such as a printer stores software required to drive the printer. That is, when power is supplied to the printer, the printer is operated by the software stored in the memory, and the printing is performed or stopped by the software according to a command instructed by the user.

In addition, the memory provided in the printer stores a value calculated for the consumption or remaining amount of consumables consumed according to the usage of the printer. That is, in the case of a laser printer, the toner and the drum generally calculate the usage amount according to the number of printed papers, so each time a printing operation is performed, the counter in the laser printer counts the number of printed papers and counts the value. Will be saved. In this way, the stored counted value is used as basic information for determining the usage amount of the toner and the drum and informing the user of the replacement time, so that data changed according to the use of the printer requires continuous storage.

As described above, the data stored in the memory as a printer has been briefly described. However, most electronic products have a memory for the same reason as described above, and the memory includes various kinds of software and various kinds of software required to drive the system as described above. Save the data.

Next, a configuration of a conventional memory will be described with reference to the accompanying drawings.

As shown in FIG. 1, conventionally, an EPROM (2) for storing software instructions for driving a system as a read only memory and a command from the EPROM (2) control system operation. A controller 1, a SRAM (static random access memory) 3 for storing data which can be read / write and which data to be kept even when the power is turned off while the system is in use, and the SRAM ( 3) a battery 4 for supplying power, an EEPROM 5 capable of reading / writing data and storing changed data even when the power is turned off, and an address / data bus for data transfer between the controller and memory ( 6). In the above configuration, the EEPROM 5 is usually 1K bits, and its memory size is very small.

According to this configuration, after power is supplied, the controller 1 receives a command from the EPROM 2 via the bus 6 to drive the system, and the controller 1 receives data changed during the use of the system. Through the SRAM 3 or the EEPROM 5, it is stored.

In other words, when the printer is described as an example, the software necessary to drive the printer is stored in the EPROM 2, and when the power is supplied to the printer, the controller 1 is stored in the EPROM 2 The system is driven by software. That is, the software stored in the EPROM 2 can only read, and cannot modify or store data unless the user uses a separate device (ultraviolet eraser).

Therefore, it is the SRAM 3 or the EEPROM 5 that has a separate memory capable of reading / writing data in the system.

The SRAM 3 or the EEPROM 5 stores data changed during the use of the system, that is, a value counting the number of sheets of printed paper in the case of a printer, or changed contents of software stored in the EPROM 2. . At this time, the data stored in the SRAM 3 or the EEPROM 5 is updated and stored every time a printing operation is performed.

That is, since the EPROM for storing software according to system operation is a fixed memory in the memory configuration of a conventional system, another memory means (SRAM or EEPROM) capable of updating and storing data changed during use of the system must be separately provided. There was this.

In addition, EPROMs are generally increased in multiples of 1K bytes, 2K bytes, 4K bytes, etc., and according to the specifications of the system, if a few megabytes are used, there is a problem that no utilization is possible even if a large amount of memory remains.

Accordingly, an object of the present invention is to provide a memory management apparatus capable of optimizing the function of the memory required by the system by the flash memory capable of read / write.

A memory management apparatus according to the present invention for achieving the above object is possible to read / write data, the memory means for storing the system command code and data changed during the use of the system; And control means for driving the system by reading the system command code stored in the memory means and designating a storage area of data input to the memory means.

The memory management apparatus of the present invention uses a flash memory capable of reading / writing data. The flash memory updates and stores the software required to run the system and the data changed during use of the system. That is, a surplus portion of the flash memory is allocated to an area for storing data that is changed during the use of the system, and under the control of the controller, data that is changed during the use of the system is updated or stored, or software necessary for driving the system is made.

Hereinafter, a memory management apparatus according to the present invention will be described in detail with reference to the accompanying drawings.

2 is a block diagram showing a memory management apparatus according to the present invention.

The configuration is described. Flash Memory (13), which stores data that can be read / written and stored while the system is in use, and software commands for driving the system. And a controller 11 that receives commands from the flash memory 13 to control a system operation, an address / data bus 14 for data transfer between the controller 11 and the flash memory 13, and the flash. It includes a memory management circuit 12 for preventing software instructions stored in the memory 13 from being changed by an error during system use.

3 is a detailed circuit diagram of a memory management apparatus according to the present invention.

The controller 11 transmits a specific address and data to the flash memory 13 through the address / data bus 14, and the flash memory 13 stores the necessary software for driving the system and uses the surplus memory left in the system. Allocates to the area to save the data to be changed.

In order to prevent the software command stored in the flash memory 13 from being changed by an error while using the system, the controller 11 enables the write signal WR # and the general output terminal signal GP10. When enabled, the write terminal WE # of the flash memory 13 is enabled through the AND gate AND.

4 is a flowchart illustrating the operation of the memory management apparatus according to the present invention.

Next, an operation process of the memory management apparatus according to the above configuration will be described in detail.

When the power is supplied, the controller 11 determines whether the user's command is a process for reading or writing data (step 100 in FIG. 4).

When performing the process by reading the data READ in step 100, the controller 11 enables the read terminal RD # to be stored in the flash memory 13 through the bus 14. Read the software instruction (step 102 of FIG. 4).

After performing the step 102, the controller 11 executes the read command (step 104 of FIG. 4).

Next, the controller 11 attempts to change a software command of the flash memory 13 from an input device (that is, a terminal connected to a computer) while executing the command of the flash memory 13 or the flash memory 13 during system operation. When inputting a signal that changes the data in the surplus memory of the controller, it is ready to enable the write terminal (WR #) and the current mode is for PC down load or data update (date). up date).

That is, first, the controller 11 determines whether the input command is a process performed by a read or a process performed by a light in step 100, and when the process is performed by a light, the currently executed mode is a personal computer ( PC) in the download mode (step 106 of FIG. 4).

In the PC download mode according to the 106th step, the general output terminal signal GP10 and the write signal WR # are enabled, and the output signal of the AND gate AND is finally enabled, thereby enabling the data bus 14. The operation of modifying the software command in the flash memory 13 by the data applied through (step 108 of FIG. 4). At this time, the chip selector terminal CS # of the controller 11 is also enabled.

When it is not the PC download mode in step 106, it is determined whether it is the data update mode (step 110 in FIG. 4), and when the currently performed mode is the data update mode, the controller 11 writes a write signal. Enable (WR #) and general output terminal signal GP10. When the two signals are enabled, the output signal of the AND gate AND is also enabled to update and store data changed during use of the system stored in the redundant memory in the flash memory 13 (step 112 of FIG. 4). In this case, the chip selector terminal CS # of the controller 11 is not enabled, and data input through the data bus 14 is updated and stored at the address designated by the controller 11. At this time, an area in which data input through the data bus 14 is stored becomes a surplus memory portion in which the flash memory 13 stores software necessary for driving the system.

In the above description, when changing the software command stored in the flash memory 13 occurs less than a predetermined time during the use of the product, the data update process for storing the data that is changed during the use of the system occurs from time to time during the use of the system In order to prevent the write terminal WR # from being enabled when the data update mode is not the PC down mode, when the write signal and the general output terminal signal are both enabled by the controller 11, the flash memory ( By performing the data write operation of 13), unnecessary damage to the stored data is suppressed.

As described above, the memory management apparatus according to the present invention uses a flash memory that is similar in price to a conventional EPROM but can read / write data, and stores software instructions necessary for driving the system, and uses the system in the remaining surplus memory. By storing the data to be changed during the implementation of the memory means by one chip at the same time there is an advantage that can be optimized in the use of the memory.

In addition, in order to prevent the software instructions stored in the flash memory from being changed by an error while using the system, the memory management circuit is used to suppress unnecessary damage of the data stored in the flash memory, thereby improving the stability of the system.

Claims (3)

Memory means capable of reading / writing data and storing system command codes and data changed during use of the system; And control means for reading a system command code stored in the memory means to drive the system and designating a storage area of data input to the memory means. The method of claim 1, And a management means for managing an enable state of the write terminal of the memory means by a control signal applied from the control means during the data write operation of the memory means. The method of claim 2, The data changed during the use of the system stored in the memory means is stored in the remaining memory after storing the system command code.