KR100758282B1 - Apparatus for managing memory using bitmap memory and its method - Google Patents

Abstract

The present invention relates to a memory management apparatus and method for minimizing data memory allocation and release time by managing data memory using a bitmap memory and to prevent wasting space of the data memory. A memory management apparatus, comprising: a data memory for storing the data; A bitmap memory mapped one-to-one with each block of the data memory to indicate an allocated / release state of the data memory; An information memory for storing information of the data memory and the bitmap memory; And calculates an address of a data memory block to be allocated next by referring to the bitmap memory and the information memory according to a memory request of a specific application program, and when the memory block is allocated, updates the bitmap memory and the information memory. And control means for calculating a value of a column and a row of the bitmap memory from an address of a data memory block which is released when the use of the data memory is completed, and updating the bitmap memory and the information memory.

Bitmap memory, data memory, bitmap details, memory information, memory allocation / deallocation

Description

Apparatus for managing memory using bitmap memory and its method

1 is a view for explaining a hierarchy to which the memory management unit according to the present invention;

2 is a configuration diagram of an embodiment of a wireless communication terminal managing a memory using a bitmap memory according to the present invention;

3 is an exemplary diagram of a wireless communication terminal memory structure managing a memory using a bitmap memory according to the present invention;

4 is an exemplary diagram of a bitmap memory according to the present invention;

5 is a flowchart illustrating a method of allocating a memory using a bitmap memory in a wireless communication terminal according to the present invention;

6 is an exemplary diagram of a program code for allocating a memory using a bitmap memory in a wireless communication terminal according to the present invention;

7 is a flowchart illustrating a method of releasing a memory using a bitmap memory in a wireless communication terminal according to the present invention;

8 is an exemplary view of a program code for releasing a memory using a bitmap memory in a wireless communication terminal according to the present invention.

* Explanation of symbols for the main parts of the drawings

210: control unit 220: memory management unit

230: internal memory 240: external memory

The present invention relates to a memory management apparatus using the bitmap memory and a method thereof, and more particularly, to manage the data memory using the bitmap memory to minimize the data memory allocation and release time, and wasted space of the data memory It relates to a memory management apparatus and method thereof for preventing it.

In the following example, a wireless communication terminal will be described as an example. However, it should be noted that the present invention is not limited thereto.

In the present invention, a wireless communication terminal is a mobile communication terminal, a personal mobile communication terminal (PCS), a personal digital terminal (PDA), a smart phone, a next generation mobile communication terminal (IMT-2000), such as a wireless terminal while carrying a person A terminal capable of wireless communication.

There may be various advantages of the wireless communication terminal, but above all, the greatest advantage is in the mobility provided to the user who is calling. Due to this mobility, the number of wireless communication subscribers has increased exponentially, and in recent years, wireless communication terminals are widely used by the general public.

However, as time goes by, the merits of mobility have gradually disappeared to users of wireless communication terminals, and a multifunctional wireless communication terminal capable of providing more various additional services is required.

Accordingly, most recently released wireless communication terminals have various functions such as camera function, radio broadcast reception function, music (for example, MP3: MPEG layer 3) playback function, acupressure function, blood glucose detection function, ultrasonic imaging function, etc. It has a function. In particular, the music playback function is one of the additional features that are in the spotlight of the young generation.

On the other hand, as the additional functions are added to the wireless communication terminal as described above, the frequency of storing data in the memory increases, and accordingly, there is a need for a method of effectively managing the memory.

On the other hand, the memory allocation and release method provided by the conventional wireless communication terminal is available at any moment when repeatedly performing the variable block allocation / deallocation of the variable size due to the universality of accommodating data structures of various sizes as a mechanism Many unsuccessful memory fragments occur frequently, and as a result, memory fragments can sometimes fail to allocate memory even if the total amount of available memory is sufficient.

For example, suppose a total of 1000 bytes of memory were allocated in the order of 300 bytes first, then 500 bytes, and then the third 200 bytes.

If there is an additional 400 bytes of memory block allocation request with the first 300 bytes and the second 200 bytes of memory blocks freed (the allocation of memory blocks must consist of consecutive bytes), 400 consecutive bytes of memory Since is not available, no further allocation is possible. Therefore, even if the totally assignable memory is 500 bytes, it is impossible to allocate 400 bytes of memory.

As described above, when the memory allocation scheme is applied to a wireless communication terminal requiring high-speed packet transmission, it is likely to generate a large number of memory fragments, thereby degrading the overall performance of the wireless communication terminal.

In addition, since the memory is divided into a variable size as described above, it takes a lot of time to determine whether the memory of the required size exists, reducing the overall performance of the wireless communication terminal.

The present invention has been proposed to solve the above problems, and a memory management apparatus for minimizing the data memory allocation and release time by managing the data memory using a bitmap memory, and to prevent wasting space of the data memory; The purpose is to provide a method.

Other objects and advantages of the present invention can be understood by the following description, and will be more clearly understood by the embodiments of the present invention. Also, it will be readily appreciated that the objects and advantages of the present invention may be realized by the means and combinations thereof indicated in the claims.

An apparatus of the present invention for achieving the above object is a memory management apparatus using a bitmap memory, comprising: a data memory for storing data; A bitmap memory mapped one-to-one with each block of the data memory to indicate an allocated / release state of the data memory; An information memory for storing information of the data memory and the bitmap memory; And calculates an address of a data memory block to be allocated next by referring to the bitmap memory and the information memory according to a memory request of a specific application program, and when the memory block is allocated, updates the bitmap memory and the information memory. And control means for calculating a value of a column and a row of the bitmap memory from an address of a data memory block which is released when the use of the data memory is completed, and updating the bitmap memory and the information memory.

On the other hand, the method of the present invention, in the memory management method using a bitmap memory, by referring to the bitmap memory and information memory in accordance with the memory request of a specific application program to calculate and return the address of the next data memory block to be allocated A memory allocation step of updating the bitmap memory and the information memory accordingly; And a memory releasing step of calculating a value of a column and a row of the bitmap memory from an address of a data memory block released as the specific application finishes using the data memory, and updating the bitmap memory and the information memory accordingly. It includes.

The above objects, features and advantages will become more apparent from the following detailed description taken in conjunction with the accompanying drawings, whereby those skilled in the art may easily implement the technical idea of the present invention. There will be. In addition, in describing the present invention, when it is determined that the detailed description of the known technology related to the present invention may unnecessarily obscure the gist of the present invention, the detailed description thereof will be omitted. Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1 is a view for explaining a hierarchy to which the memory management unit according to the present invention belongs.

As shown in FIG. 1, the wireless communication terminal has a media access control (MAC) layer and a physical (HY) layer. The MAC layer is responsible for transmitting and receiving data through an interface with a higher layer and a PHY layer. In this case, the PHY layer is responsible for transmitting data received from the MAC layer to a wireless channel in space and also transmitting data received from the wireless channel to the MAC layer.

On the other hand, the wireless communication terminal includes a memory management unit for performing the SDU assembly associated with the transmission and reception of the SDU (or SDU (Service Data Unit)) input in the MAC layer.

2 is a block diagram of an embodiment of a wireless communication terminal managing a memory using a bitmap memory according to the present invention.

As shown in FIG. 2, a wireless communication terminal for managing a memory using a bitmap memory according to the present invention includes a control unit 210 for controlling overall control of the wireless communication terminal, a control unit for storing data at high speed. The internal memory 230, and an external memory 240 for storing a large amount of data.

In addition, the controller 210 includes a memory manager 220 that is implemented in software or hardware and is responsible for allocating and releasing an internal memory or an external memory.

3 is an exemplary diagram of a wireless communication terminal memory structure managing a memory using a bitmap memory according to the present invention.

As shown in FIG. 3, a wireless communication terminal memory managing a memory using a bitmap memory according to the present invention includes an information memory area, a data memory area, and a bitmap that store information of a data memory and a bitmap memory. It includes a memory area.

On the other hand, "memInfoAddr" in the information memory is a memory address of an area for information of the data memory and the bitmap memory.

Information on the data memory and bitmap memory includes "baseAddr", "size", "blkSize", "numBlk", "numBtm", "hdrAddr", and "btmAddr".

Here, "baseAddr" indicates the address of the first block of the data memory area for storing actual data. "Size" represents the total data memory block for storing actual data in bytes, and "blkSize" represents the size of the fixed memory block. That is, it shows the size of a block for storing a fixed size data structure.

&Quot; numBlk " represents the number of fixed-size memory blocks, " numBtm " represents the size of the information group representing one-bit information indicating the allocation / release state of the memory block in 32-bit units, and " btmAddr " Indicates a bitmap memory address.

And "hdrAddr" points out the address of the memory area which stores bitmap memory detailed information which shows allocation status information of the data memory which stores actual data.

On the other hand, the bitmap detailed information indicating the state of the bitmap memory includes "flag", "numFreeBlk", "btmRow", and "btmCol".

Here, "btmRow" refers to the number of the row of the bitmap memory indicating the block number of the next allocated data memory, and "btmCol" refers to the number of the column of the bitmap memory indicating the block number of the next allocated data memory. .

Therefore, by combining the "btmRow" and "btmCol", the block number of the next data memory to be allocated can be known.

In addition, "flag" is an indicator indicating that an operation of allocating or releasing data memory blocks indicated by "btmRow" and "btmCol" is currently in progress. If this indicator is 1, it indicates that memory is in use. If "flag" is 1, the data memory block indicated by "btmRow" and "btmCol" cannot be used in another application.

That is, "flag" is set to 1 at the same time when the data memory blocks pointed to by "btmRow" and "btmCol" are allocated in a specific application, and the data memory block pointed by "btmRow" and "btmCol" in other applications. Prevents the use of.

For example, if two applications want to simultaneously allocate the data memory block indicated by the "btmRow" and "btmCol", a certain application of the two applications first needs to be "btmRow" and "btmCol". When the data memory block pointed to is allocated, the value of "flag" is changed to 1 so that the remaining applications cannot be allocated the data memory block pointed to by "btmRow" and "btmCol".

If two application programs are simultaneously allocated the same data memory block, normal data cannot be stored in the data memory block, causing the wireless communication terminal to malfunction.

&Quot; numFreeBlk " represents the number of currently assignable data memory blocks.

On the other hand, the number of the currently assignable data memory block is calculated by the following Equation 1 using the bitmap detailed information.

Assignable Data Memory Block Number = btmRow * 32 + btmCol

Therefore, the absolute address of the data memory block that is actually allocated is calculated by Equation 2 below.

Address of assignable data memory block = baseAddr + blkSize * [Equation 1]

On the other hand, the data memory as described above is not divided into only one size. In other words, data memory blocks are not classified by one size of "blkSize", but are classified according to each size by predicting the size of a program requested by an application in advance.

Therefore, the size of the memory block is not one, but various, and accordingly, there are separate bitmap memory and bitmap detailed information for indicating the allocation / release state of the memory block, and also the bitmap memory and the different There is a separate information memory for representing information of a memory block of size.

For example, when the size of a program requested by an application program is 200 bytes, 300 bytes, or 400 bytes, the data memory has a predetermined number of memory blocks, each of 200 bytes, 300 bytes, and 400 bytes. Memory blocks of each size are continuously located, and there are bitmap memory and information memory for managing memory blocks of each size, respectively.

Thus, when an application program requests a program, the memory manager 220 of the controller 210 loads the program into the memory by referring to the information memory and the bitmap memory corresponding to the size of the program, thereby allocating a memory allocation / release time. In addition, since the memory is not divided into variable sizes, memory fragments can be prevented from being allocated or deallocated.

In addition, there is a bitmap memory and an information memory according to the size of each memory block, thereby minimizing memory allocation / release time.

4 is an example of a bitmap memory for memory management according to the present invention.

As shown in FIG. 4, each bit of the bitmap memory for memory management according to the present invention is mapped one-to-one with a corresponding data memory block and represents the number of the corresponding data memory block by a combination of btmRow / btmCol. That is, the data memory block number mapped to the bits of the i th row and the j th column is (i * 32 + j). If a data memory block mapped to the bits of the i-th row and the j-th column is currently allocated, it is set to "1", and the data memory block mapped to the bits of the i-th row and the j-th column is currently released. If the status is set to "0", it indicates the allocation / release status of the current data memory block.

5 is a flowchart illustrating a method of allocating a memory using a bitmap memory in a wireless communication terminal according to the present invention.

First, when a specific application program requests memory to be allocated, the controller 210 determines whether the number of currently assignable data memory blocks of the data memory block corresponding to the size of the data memory block requested to be allocated is greater than zero, that is, the current The existence of the allocable data memory block is checked using the value of "numFreeBlk" in the bitmap detailed information (510).

As a result of the check 510, if the value of "numFreeBlk" corresponding to the size of the requested data memory block is smaller than 0, that is, if no data memory block is currently allocated, an error code is returned (520). Inform that there is no allocable data memory block, and take countermeasures such as expanding the data memory capacity.

On the other hand, when the check result 510, the value of "numFreeBlk" corresponding to the size of the requested data memory block is greater than zero, the controller 210 uses the bitmap detailed information and the bitmap memory to The address of the data memory block to be allocated by Equation 2 is calculated (530).

Thereafter, the controller 210 sets the bit value indicating the data memory block to be allocated in the bitmap memory to "1" using "btmRow" and "btmCol" in the bitmap detailed information (540).

Thereafter, the controller 210 decreases the value of "numFreeBlk" in the bitmap detailed information by 1 (550) so that the number of allocable data memory blocks is decreased by 1, and the value of the bitmap memory indicating the next data memory block to be allocated. The values of "btmRow" and "btmCol" in the bitmap detailed information are set as row and column values (560).

In this case, the "btmRow" and "btmCol" are set to the value of the column and the row of the bitmap indicating the closest assignable data memory block from the value of the column and the row of the bitmap indicating the data memory block to be currently allocated.

Thereafter, the address of the data memory block to be allocated is returned to the application program requesting the allocation of the memory (570) so that the data memory can be allocated.

FIG. 6 shows the above memory allocation method in pseudo code.

By allocating the data memory in the above manner, it is possible to save the allocating time of the allocable data memory block, thereby minimizing the execution time of the wireless communication terminal.

7 is a flowchart illustrating a method of releasing a memory using a bitmap memory in a wireless communication terminal according to the present invention.

First, when the controller 210 informs that a specific application has completed the use of the data memory, the block of the data memory to be released using the size and the address of the data memory block to which the specific application has been allocated, i. A column and a row of the bitmap memory pointed to are computed (710).

Thereafter, the bit values corresponding to the columns and rows of the computed bitmap memory are set to "0" (720), and the value of "numFreeBlk" representing the number of assignable data memory blocks in the bitmap detailed information is increased by one. (730).

Thereafter, the controller 210 checks whether the number of currently allocated data memory blocks is one (740). That is, it is checked whether the value of "numFreeBlk" indicating the number of allocable data memory blocks in the bitmap detailed information is 1.

As a result of the check 740, when the number of currently allocated data memory blocks is 1, the values of "btmRow" and "btmCol" in the bitmap detailed information are present because the data memory block to be released is the next data memory block to be allocated. A value of a column and a row of the bitmap memory indicating the data memory block to be released is set (750).

As described above, when there is a data memory block that can be allocated when the current memory block is released, that is, when all data memory is currently allocated, the columns and rows of the bitmap memory indicating the next block of the data memory that can be allocated among the bitmap detailed information. The value of can not be set to any particular value since there is no next block of data memory that can be allocated.

Therefore, in this case, all bit values of "btmRow" and "btmCol" are set to a specific value such as "1" to indicate that there is no data memory block currently allocated.

Therefore, the values of the columns and rows of the bitmap indicating the data memory block which are currently released are set to the values of "btmRow" and "btmCol".

On the other hand, if the check result 740, the number of currently allocated data memory blocks is not 1, already "btmRow" and "btmCol" is the value of the column and row of the bitmap memory indicating the next assignable data memory block It is set so that there is no need to change it.

Therefore, the release process of the data memory block is immediately terminated.

FIG. 8 illustrates a method of releasing the memory as a pseudo code.

As described above, by estimating the size of the requested memory block in advance, and consequently placing memory blocks of the same size in succession, it is possible to prevent the occurrence of unusable pieces of memory when conventional data memory is allocated and released. Also, by managing the allocation / release of the data memory block using the bitmap memory, the performance of the wireless communication terminal can be improved by minimizing the memory allocation / release time.

As described above, the method of the present invention may be implemented as a program and stored in a recording medium (CD-ROM, RAM, ROM, floppy disk, hard disk, magneto-optical disk, etc.) in a computer-readable form. Since this process can be easily implemented by those skilled in the art will not be described in more detail.

The present invention described above is capable of various substitutions, modifications, and changes without departing from the technical spirit of the present invention for those skilled in the art to which the present invention pertains. It is not limited by the drawings.

As described above, the present invention can predict the size of a requested memory block in advance, and accordingly, by sequentially placing memory blocks of the same size, it is possible to prevent the occurrence of unusable pieces of memory when the memory is allocated and released. It works.

In addition, the present invention has the effect of minimizing the memory allocation / release time by managing the allocation / release of memory blocks divided according to the size of the program using a bitmap memory to improve the performance of the electronic device.

Claims (10)

In the memory management apparatus using a bitmap memory, A data memory for storing data; A bitmap memory mapped one-to-one with each block of the data memory to indicate an allocated / release state of the data memory; An information memory for storing information of the data memory and the bitmap memory; And The data memory block address to be allocated next is calculated by referring to the bitmap memory and the information memory according to a memory request of a specific application program, and when the memory block of the data memory is allocated, the bitmap memory and the information memory are changed. Control means for updating the bitmap memory and the information memory, calculating a value of a column and a row of the bitmap memory from a block address of the data memory which is released when the use of the data memory is completed. Memory management apparatus using a bitmap memory comprising a. The method of claim 1, The information memory, The first address (baseAddr) of the data memory, The total size of the data memory, A fixed block size (blkSize) of the data memory, Number of fixed blocks of the data memory (numBlk), Number of bit groups of the bitmap memory (numBtm), An address hdrAddr representing a bitmap memory information, and First address of the bitmap memory (btmAddr) Memory management apparatus using a bitmap memory, characterized in that it comprises a. The method of claim 2, The bitmap detailed information, A value (btmRow) of a row of the bitmap memory indicating a data memory block to be allocated next, A value (btmCol) of a column of the bitmap memory indicating the next data memory block to be allocated, A flag indicating a status of allocating / releasing a data memory block indicated by the columns and rows of the bitmap memory, and Number of currently allocated data memory blocks (numFreeBlk) Memory management apparatus using a bitmap memory, characterized in that it comprises a. The method of claim 3, wherein The data memory block sizes are divided by a predetermined number according to the size of the requested program, and the bitmap memory and the information memory are respectively present according to the data memory blocks of different sizes. Memory management device using. delete The method of claim 1, The control means, The number of data memory blocks to be allocated next is calculated according to Equation 1 below, And a physical address of the next data memory block to be allocated according to Equation 2 below. [Equation 1] Assignable Data Memory Block Number = btmRow * 32 + btmCol In Equation 1, "btmRow" indicates the number of the row of the bitmap memory indicating the block number of the next allocated data memory, and "btmCol" indicates the number of the column of the bitmap memory indicating the block number of the next allocated data memory. Point to. [Equation 2] Address of assignable data memory block = baseAddr + blkSize * [Equation 1] In Equation 2, "baseAddr" represents the address of the first block of the data memory area, and "blkSize" represents the fixed block size of the data memory. In the memory management method using a bitmap memory, A memory allocation step of calculating and returning an address of a data memory block to be allocated next by referring to a bitmap memory and an information memory according to a memory request of a specific application program and updating the bitmap memory and the information memory accordingly; And A memory releasing step of calculating a value of a column and a row of the bitmap memory from an address of a data memory block released as the specific application finishes using the data memory and updating the bitmap memory and the information memory accordingly Memory management method using a bitmap memory comprising a. The method of claim 7, wherein The memory allocation step, Checking a size of a data memory block requested by the specific application program; Checking the number of allocable memory blocks of the checked data memory blocks; Calculating an address of a data memory block to be allocated by Equation 1 and Equation 2 as the identified allocable data memory block is greater than zero; Setting a bit value of a bitmap memory indicating an address of the data memory block to be allocated to a predetermined value; Reducing the number of assignable data memory blocks of the bitmap detailed information by one; A bitmap memory row value (btmRow) and a bitmap memory column value (btmCol) of a bitmap memory row of bitmap detail information as a column and row value of a bitmap memory bit value representing an assignable data memory block closest to the data memory block to be allocated. Setting up; And Returning the computed address of the data memory block to be allocated Memory management method using a bitmap memory comprising a. [Equation 1] Assignable Data Memory Block Number = btmRow * 32 + btmCol In Equation 1, "btmRow" indicates the number of the row of the bitmap memory indicating the block number of the next allocated data memory, and "btmCol" indicates the number of the column of the bitmap memory indicating the block number of the next allocated data memory. Point to. [Equation 2] Address of assignable data memory block = baseAddr + blkSize * [Equation 1] In Equation 2, "baseAddr" represents the address of the first block of the data memory area, and "blkSize" represents the fixed block size of the data memory. The method according to claim 7 or 8, The memory release step, Identifying a size of a data memory block that the particular application has completed using (to be released); Calculating a column and row value of a bitmap memory corresponding to the identified data memory block from an address of the data memory block to be released; Setting bit values of bitmap memories corresponding to columns and rows of the computed bitmap memory to predetermined values; Increasing the number of assignable data memory blocks of the bitmap detailed information by one; Checking whether the number of the assignable data memory blocks is 1; And The value of the bitmap memory row (btmRow) and the bitmap of the bitmap detailed information is determined by the value of the column and the row of the bit value of the bitmap memory indicating the data memory block to be released according to the number of the allocable data memory blocks identified as one. Setting the value of the map memory column (btmCol) Memory management method using a bitmap memory comprising a. The method of claim 9, The bitmap detailed information, A value (btmRow) of a row of the bitmap memory indicating a data memory block to be allocated next, A value (btmCol) of a column of the bitmap memory indicating the next data memory block to be allocated, A flag indicating a status of allocating / releasing a data memory block indicated by the columns and rows of the bitmap memory, and Number of currently allocated data memory blocks (numFreeBlk) Memory management method using a bitmap memory comprising a.

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