KR100219160B1 - Apparatus of owning a memory jointly - Google Patents

Abstract

Description of the Related Art [0002] The present invention relates to a memory sharing device used in a video on demand (VOD) set-top box that provides desired video data in real time at a desired time of a subscriber. The apparatus of the present invention includes a CPU for performing overall control and outputting a command for a required function, a plurality of devices for receiving a command output from the CPU and performing a corresponding function, A single memory unit allocated to the area, and a logic unit for controlling the plurality of devices to appropriately use the area allocated to the single memory unit. Therefore, the present invention provides an effect of using the memory more efficiently by sharing the memory area while reducing the amount of memory used.

Description

Memory Sharing Device

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a Video On Demand (VOD) set-top box that provides desired video data (Data) in real time at a desired time, and more particularly to a memory sharing device used in a set- .

In general, a set-top box used as a terminal device of a multimedia network connects a digital / analog (D / A) communication channel with a user's multimedia. On the other hand, the memory device of the set-top box has a large amount of memory because a separate memory is connected to each device. Such a conventional memory device is shown in Fig.

1 is a block diagram showing a memory device in a conventional set-top box, in which a central processing unit (hereinafter referred to as CPU) 11 issues a command and the first and second devices 12, 11 and the first and second memory units 14 and 17 are connected to corresponding devices 12 and 15 to store and read data necessary for the corresponding operation . In addition, the controllers 13 and 18 are connected between the devices 12 and 15 and the memory units 14 and 17, respectively, and control so that necessary data can be exchanged.

However, in the conventional memory device configured as described above, memory areas required for the first device 12 and the second device 15 to operate in accordance with instructions from the CPU 11 are different from each other. In addition, when only the first device 12 is operated, an extra memory area is created in the second memory unit 17, and vice versa. In conclusion, there are only two memory sections. That is, each memory device must be connected to each memory device. Therefore, since all the memories are not used at the same time, the memory occupies an extra portion that is not used. As a result, the amount of the memory element is increased.

SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a first memory unit 12 for more efficiently using a memory area of a memory device used in a set- And to control the area in the logic unit 24 and share the same in a single memory unit.

1 is a block diagram showing a conventional memory device; Fig.

FIG. 2 is a block diagram showing a memory sharing apparatus according to a preferred embodiment of the present invention; FIG.

DESCRIPTION OF THE REFERENCE NUMERALS

11, 21: central processing unit (CPU) 12, 15, 22, 23:

13, 16: controller 14, 17, 25:

24:

According to an aspect of the present invention, there is provided a memory device for a plurality of devices, the memory device including: a CPU for performing overall control and outputting a command for a required function; A single memory unit allocated to a shared area shared by a plurality of devices and respective fixed areas for a plurality of devices and a plurality of devices sharing a shared area allocated to a single memory unit And a logic unit for controlling the recording and reading of data.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

2 is a block diagram showing a memory sharing apparatus according to the present invention. As shown in the figure, the apparatus of the present invention is configured in the same manner as the conventional apparatus shown in Fig. 1, except that each of the devices 22 and 23 And a logic unit 24 for controlling each of the devices 22 and 23 and the single memory unit 25. The single memory unit 25 is used as a fixed area and a shared area of a single memory unit 25,

The operation of the memory sharing apparatus having the above-described structure will be described in more detail.

First, the CPU 21 designates not only the data of the necessary operation command for each of the devices 22 and 23, but also an address for memory use. For example, when the CPU 21 allocates the address of the third device 22 from 0 to 1FFFFFH and the address of the fourth device 23 from 200000H to 3FFFFFH, An address of 2 Mbyte is allocated. Of these, only 1 Kbyte is always used for the third device 22, and 1 Kbyte is always used for the fourth device 23 as well. Thus, the memory unit 25 has a fixed area where each device 22, 23 is always used. The areas excluding 1 Kbytes in each of the devices 22 and 23 are not always used by the third and fourth devices 22 and 23 but are used only by the CPU 21 when performing the corresponding function. In addition, since each of the devices 22 and 23 does not perform the corresponding function at the same time, in the present invention, each 1Kbyte fixed area of the memory unit 25 is allocated to each of the devices 22 and 23, Through the logic unit 24.

That is, when the third device 22 is a graphic processor and the fourth device 23 is an MPEG decoder, when an instruction to display a graphic on the CPU 21 is applied to the third device 22 The graphics processor of the third device 22 performs graphic processing using the fixed area and the shared area of the memory part 25 via the logic part 24 to display graphics on the screen. On the other hand, when a command is applied from the CPU 21 to the fourth device 23 as an MPEG decoder, the MPEG decoder performs an MPEG command using the fixed area and the shared area of the memory part 25 through the logic part 24 do. Here, during the processing of the MPEG data, the graphic data stored in the shared area of the memory unit 25 becomes unnecessary.

At this time, the logic unit reads and writes data to the address of the corresponding memory by the signals output by the graphics processor and the MPEG decoder.

As described above, the present invention provides a memory sharing device used in a set-top box, thereby reducing the amount of memory used and sharing the memory area.

Claims (2)

1. A memory device for a plurality of devices, comprising: a CPU for performing overall control and outputting commands for necessary functions; A plurality of devices for receiving a command output from the CPU and performing a corresponding function; A single memory unit allocated to each fixed area for the plurality of devices and a shared area shared by the plurality of devices; And a logic unit for controlling the plurality of devices to share and share data allocated to the single memory unit. The memory sharing apparatus according to claim 1, wherein the CPU outputs a command such that the plurality of devices do not simultaneously use the shared area of the memory unit.