JPH0635795A - Option card of personal computer - Google Patents

Abstract

PURPOSE:To make it possible to utilize a video memory of an option card mounted on the extension slot of a personal computer by automatically making it an image memory or a general purpose memory. CONSTITUTION:This system is provided with a buffer part 10 making data buses 8, 9 between the side of a personal computer 3 and the video memory 1 of an option card be in a connection state and a disconnection state, a control circuit 11 making the data buses 8, 9 in the disconnection state by turning OFF the buffer part 10 when the personal computer 3 starts to operate (at the time of a rise), making the data buses 8, 9 in the connection state by turning on the buffer part 11 after a memory check at the time of the start of the operation is terminated and making the data buses 8, 9, be in the connection state by the switching control of a selector a ROM 2a storing the switching data of the selector 11d and an image processing part 2b reading the data of this ROM 2a and controlling the selector 11d.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an option card for a personal computer equipped with a video memory for processing an input video signal in a predetermined manner. More specifically, the video memory is used for image processing. The present invention relates to an option card for a personal computer, which can be used as a general-purpose video memory and can be automatically switched.

[0002]

2. Description of the Related Art In recent years, the processing speed of personal computers has become faster, and various processes have become smoother. Therefore, the popularity of personal computers tends to increase.

Further, the above personal computer is equipped with various optional devices in order to meet the user's specifications. Memory access and I
Although there is an I / O access, the memory access has a faster access time than the I / O access.

Therefore, even in the option card shown in FIG. 2, for example, as the above-mentioned optional device, the above memory access method is adopted. The option card includes an image processing section (processor) 2 for predetermined processing of an input video signal in addition to the video memory 1, and is mounted in an expansion slot 4 of a main body of the personal computer 3. Further, the option card is provided with a video signal input terminal 5 for inputting an input video signal, a monitor output terminal 6 for outputting the image data of the video memory 1 to a monitor device, and the like.

The address bus, data bus, I / O, and read (R) of the personal computer 3 are
EAD) and write (WRITE) control signals are input to and output from the option card. As a result, the personal computer 3 can freely write and read the video memory 1 through the data bus 7 at high speed, and various image processes can be performed.

[0006]

By the way, at the time of starting the operation of the above personal computer, that is, at the time of starting up (when the power is turned on), the memory usable by the normal OS is checked, that is, the memory space available by this check. Is determined and the area of this memory space is O
Managed by S.

Regarding the memory check at the time of starting the above operation, after clearing the entire memory space (after 00 (H)), 00 (H) of the same memory is read and confirmed, or the entire memory space is checked. For example, AA (H) or 55 for every 1 KB at the beginning of every 256 KB
Check by writing / reading (H).

However, when the memory is checked, the video memory 1 of the option card is also checked, and the video memory 1 also enters the management of the OS as a usable memory space. The memory 1 may be used in the same manner as the normal memory, and it may not be possible to use it for image processing, which is the original function of the video memory 1.

The present invention has been made in view of the above problems, and an object thereof is to provide a video memory of an option card as an O memory.
The video memory can be used for image processing of its original function without being controlled by S, and the video memory can be used as a general-purpose memory by being controlled by the OS. Another object of the present invention is to provide an option card for a personal computer capable of automatically switching the image memory or the general-purpose memory.

[0010]

In order to achieve the above object, the present invention provides a video memory readable / writable by a personal computer main body, and an image processing for writing at least an input video signal in the video memory and performing image processing. An option card of a personal computer capable of accessing the memory of the video memory, and a buffer for connecting or disconnecting the data bus of the personal computer main body and the data bus of the video memory. Section and the personal computer main body to check the available memory space, the buffer unit is controlled to disconnect the data bus of the personal computer main body from the data bus of the video memory. personal The ON signal of the buffer unit output from the computer main body is latched to connect the data bus of the personal computer main body and the data bus of the video memory to each other, or the data bus and video of the personal computer main body are switched by the selector switching operation. A control circuit for connecting the memory data bus to the personal computer to control the buffer unit so that the personal computer can access the video memory, and switching data of the selector are stored, and via the image processing unit. And a storage unit capable of rewriting the switching data by the personal computer main body. When the personal computer main body is powered on, the image processing unit reads the switching data of the storage unit and switches the switching data. The switching of the selector is automatically controlled based on the replacement data, and the memory space of the video memory is put under the control of the OS according to the switching data of the storage means, or the memory space of the video memory is managed by the OS. The gist is that the video memory can be used as an image memory or can be used as a general-purpose memory without inserting it below.

[0011]

With the above construction, when the switching data stored in advance in the storage means enables the video memory to be used as an image memory, when the personal computer main body is powered on, that is, when it is started up, Although the entire memory space is checked, the switching data of the storage means is read by the image processing section, and the selector is controlled by the control signal based on the switching data.

At this time, since the ON signal of the buffer section is not latched, the data bus between the personal computer main body and the video memory is cut off. Therefore, access to the same video memory by the OS of the personal computer main body is invalidated, so that the above video memory does not come under the control of the above OS and the same video memory is not used as a memory space.

However, after checking all the memory spaces, the personal computer main body outputs the ON signal of the buffer section, the signal is latched by the control circuit, and the latch signal is output through the selector. Will be done.

When the video memory is accessed, the buffer section is turned on by the output signal from the selector, and the selector connects the data bus between the personal computer and the video memory so that the video memory is accessed. Is effective, and the video memory can be used as an image memory.

On the other hand, when the switching data stored in advance in the storage means makes the video memory usable as a general-purpose memory, the entire memory space is set when the personal computer main body is powered on, that is, when it is started up. Is checked, the switching data of the storage means is read by the image processing unit, and the selector is controlled by the control signal based on the switching data. By this switching control, a fixed signal (that is, a signal for turning on the buffer section) is output from the selector, so that the data bus between the personal computer and the video memory is connected.

As a result, the memory space of the video memory is checked when the memory is checked when the personal computer is powered on, that is, the memory space of the video memory is under the control of the OS. That is, the video memory can be used as a general-purpose memory instead of an image memory.

As described above, the video memory is used as an image memory or the video memory is used as a general-purpose memory by automatically controlling the selector based on the switching data stored in the storage means. It becomes possible to do.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described in detail below with reference to FIG. In the figure, the same parts as those in FIG.

In the figure, an option card for a personal computer according to the present invention includes a buffer section 10 for connecting or disconnecting the data buses 8 and 9 for enabling the personal computer 3 to access the video memory 1, and the above-mentioned. When the personal computer 3 starts the operation (when checking the memory), the buffer unit 10 is turned off (that is, the data buses 8 and 9 are turned off),
And after the memory check is completed, the buffer unit 10
To output a control signal for turning on (that is, connecting the data buses 8 and 9) or outputting a control signal for turning on the buffer unit 10 when the video memory 1 is accessed. 11 and 11.

Therefore, the control circuit 11 inputs the address from the main body of the personal computer 3 and makes the address signal A for making the video memory 1 accessible.
And an address decoder 11a which outputs a "1"("H" level) signal B during the address of the video memory 1 and a pulse signal C corresponding to the input address, The pulse signal C from the decoder 11a and I from the personal computer 3 main body
I / O from the main body of the personal computer 3 with a 3 AND circuit 11b which takes the logical product of / O and the write control signal and an output signal of the 3 AND circuit 11b as a clock
Flip-flop circuit 11c for latching the / O output (D0) signal, and Q of this flip-flop circuit 11c
A selector 11d that selects either one of the output signal and "1"("H" level) depending on the power supply voltage (Vcc);
The logical product of the signal switched by the selector 11d and the output signal B of the address decoder 11a is calculated, and the buffer circuit 10 is turned on according to the result of the logical product.
It is provided with a 2-and circuit 11e for turning off and on.

Further, this option card is an EEP-RO which stores switching data of the selector 11d.
In addition to the function of the image processing unit 2 shown in FIG. 2, an M (storage unit) 2a and an image processing unit (processor) 2b that reads the data of the EEP-ROM 2a and outputs the switching control signal of the selector 11d. Equipped with the above EEP
-ROM 2a data is the above personal computer 3
Is rewritable via the image processing section 2b.

The data buses 8 and 9 correspond to the data bus 7 shown in FIG. The reset signal (RESET) from the main body of the personal computer 3 is input to the reset terminal R of the flip-flop circuit 11c and the image processing unit 2b.

Next, the operation of the option card having the above structure will be described. First, it is assumed that the option card is installed in the expansion slot of the main body of the personal computer 3, and the EEP-ROM 2a uses the video memory as an image memory. Selector 1 above to make available
It is assumed that switching data for switching 1d is stored. Then, when the operation of the personal computer 3 is started (when the power is turned on), the OS (operating system) of the personal computer 3 checks the entire memory space (check by memory access).

At this time, the image processing unit 2b outputs E
Switching data stored in a predetermined address (0 address) of the EP-ROM 2a is read out, and switching control of the selector 11d is performed based on this data. This switching data causes the selector 11d to flip-flop circuit. Since the Q output signal of 11c is selected, the Q output signal of the flip-flop circuit 11c is output from the selector 11d. Further, the flip-flop circuit 11c is reset by turning on the power supply, and the I / O output (D0) of the main body of the personal computer 3 is kept at "0"("L" level) at the time of the memory check. Therefore, the Q output of the flip-flop circuit 11c is "0", and therefore the output signal of the selector 11d remains "0".

As a result, the 2 AND circuit 11e becomes a prohibition gate, and the output signal of the 2 AND circuit 11e is "0", so that the buffer section 10 is turned off by the signal of "0", that is, the above-mentioned. Data bus 8,
9 is disconnected.

At the time of the memory check, 00 (H) is not written to the video memory 1 and the 00 (H) is not read, that is, the memory space of the video memory 1 is not read. Is disabled. Therefore, after the memory check of the entire memory space is completed, since the access to the video memory 1 is disabled, the area of the video memory 1 is managed by the OS (operating system) of the personal computer 3. It won't go down.

However, after the operation of the memory check is completed, the original I / O output (D0) of the personal computer 3 is "1"("H"level;
N signal), and at the time of I / O writing of an address in the video memory 1, "1" of the I / O output (D0) is set in the flip-flop circuit 11c. That is, the Q of the flip-flop circuit 11c is
The output becomes "1", and the Q output of the flip-flop circuit 11c is kept at "1" until, for example, a reset is applied.

Since the selector 11d is switched to the flip-flop circuit 11c side, the signal "1" which is the Q output of the flip-flop circuit 11c is input to the 2-AND circuit 11e. This 2
The prohibition state of the AND circuit 11e is released. That is,
When the video memory 1 is accessed by the main body of the personal computer 3, the output signal B of the address decoder 11a becomes "1".
Output becomes "1" and the buffer section 11 is in the ON state, that is, the data buses 8 and 9 are connected.

As a result, even if the memory space of the video memory 1 is not under the control of the OS, access to the video memory 1 is valid when the application software is operated under the control of the OS. Therefore, normal data (not image data) is not written in the video memory 1, and the original function of the video memory 1 can be operated.

On the other hand, the data in the EEP-ROM 2a is rewritten by the personal computer 3,
Switching data for switching the selector 11d so that the video memory can be used as a general-purpose memory is written in the EEP-ROM 2a, the personal computer 3 is powered on, and the operation of the personal computer 3 is performed. It has been started.

Then, when the power of the main body of the personal computer 3 is turned on, the switching data of the EEP-ROM 2a is read by the image processing section 2b, and the switching control signal based on this data is output. As a result, the selector 11d is automatically switched to the side of the power supply voltage Vcc, that is, the selector 11d outputs the signal of "1" by the power supply voltage Vcc, so that the prohibition state of the 2-AND circuit 11e is released. It remains as it was.

Therefore, in the same manner as described above, when the video memory 1 is accessed by the main body of the personal computer 3, the signal B from the address decoder 11a is output to the buffer unit 10 via the 2-and circuit 11e, and the buffer unit 10 is turned on. That is, the data buses 8 and 9 are connected.

That is, the personal computer 3
At the time of checking the usable memory at the time of starting the main body, the connection between the data buses 8 and 9 is established, and the check of the video memory 1 is executed. Therefore, the memory space of the video memory 1 is the OS. Will be under control.

As described above, if the data to be written in the EEP-ROM 2b is changed depending on whether the video memory 1 is used as an image memory or a general-purpose memory, the personal computer 3 is turned on (operation). At the time of start), the selector 11d can be automatically switched, and the 2-AND circuit 11e can be set in the prohibited state or released from the prohibited state.

When the memory space is checked when the power of the personal computer 3 is turned on, the video memory 1 is not checked by the prohibition state of the 2 AND circuit 11e or the release of the prohibition state. The memory space of the video memory 1 can be invalidated, or the video memory 1 is checked, that is, the memory space of the same memory 1 can be validated.

Since the memory access method is used to access the option card in the personal computer 3 body, high-speed writing / reading between the personal computer 3 and the option card (video memory 1) can be realized. You can

[0037]

As described above, according to the present invention, a video memory readable / writable by the personal computer main body and an image processing unit for writing at least an input video signal in the video memory and performing image processing are provided. An option card for a personal computer that enables memory access to the video memory, and disconnects the data bus connecting the personal computer and the video memory when the personal computer starts operating (starts up). After the memory check at the same startup is completed, the same data bus is connected and the same video memory can be accessed, or the personal computer and the video memory are connected when the video memory is accessed by the selector switching control. De The server is connected, the video memory is always accessible, the switching control data of the selector is stored in advance in the storage means, and the data in the storage means is stored in the storage means by the image processing unit when the operation of the personal computer is started. Since the selector can be read out and the selector can be automatically controlled, it is possible to prevent the memory space of the video memory from being managed by the OS when the memory is checked when the personal computer is powered on. The memory can be used as an image memory, or the memory space of the video memory can be brought under the control of the OS, and as a result, the video memory can be used as a general-purpose memory, and the storage means described above. By storing the selector switching data in advance, It can be utilized automatically switched to video memory as an image memory or a general-purpose memory.

[Brief description of drawings]

FIG. 1 is a schematic block diagram of an option card showing an embodiment of the present invention.

FIG. 2 is a schematic block diagram of a conventional option card.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 video memory 2a EEP-ROM (storage means) 2b image processing unit (processor) 3 personal computer 8, 9 data bus 10 buffer unit 11 control circuit 11a address decoder 11b 3 AND circuit 11c flip-flop circuit 11d selector 11e 2 AND circuit

Claims (1)

[Claims] 1. A video memory readable / writable by a main body of a personal computer, and an image processing unit for writing at least an input video signal into the video memory and performing image processing, and enabling memory access of the video memory. An option card for a personal computer, comprising: a buffer unit for connecting or disconnecting the data bus of the personal computer main unit and the data bus of the video memory; and a check of available memory space by the personal computer main unit. Sometimes the buffer unit is controlled to disconnect the data bus of the personal computer main unit from the data bus of the video memory, and the buffer unit output from the personal computer main unit is turned on after checking the memory space. The data bus of the personal computer main body and the data bus of the video memory are connected to each other, or the data bus of the personal computer main body and the data memory of the video memory are connected by a selector switching operation, A control circuit that controls the buffer unit to enable access to the video memory by a personal computer, stores switching data of the selector, and writes the switching data by the personal computer main body via the image processing unit. When the personal computer main body is powered on, the image processing unit reads the switching data of the storage unit and automatically switches the selector based on the switching data. The video data in the memory space of the video memory according to the switching data of the storage means.
A personal computer characterized in that the video memory can be used as an image memory or a general-purpose memory without being put under the control of S or the memory space of the video memory under the control of the OS. Option card.