JPH0342714A - Backup control system for display memory - Google Patents

Abstract

PURPOSE:To back up display data by saving the content of a display memory in a backup memory immediately before main power source is cutoff. CONSTITUTION:A system memory 5 is backed up by a back up battery 8 and data to be backed up is stored in the back up memory 51 being a part of the system memory. Display data is stored in VRAM 6, and is displayed in a display device 9 through a display control circuit 7. VRAM 6 is not being backed up. Display data stored in VRAM 6 is stored in the back up memory 51 and a display data storage status memory 4 is set. After power is recovered display data stored in the backup memory 51 is transferred to VRAM 6, and is displayed in the display device 9 when the display data storage status memory 4 is set.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Application Field) The present invention relates to a display memory backup control method suitable for use in a computer system having a resume function.

(Prior technology) Equipped with a resume function that allows the contents stored in the memory (hereinafter referred to as stored data) to be erased even if the main power of the main unit is cut off, and the program can be re-executed when the power is turned on again. Personal computers are known. Usually, stored data is stored in a battery (such a battery is called a backup battery).
It is maintained (backed up) by etc. The memory that holds stored data is broadly divided into system memory, which mainly stores programs and their data, and display memory (VRAM) 02, which stores data to be displayed on a display device.

(Problem to be solved by the invention) According to the above conventional example, due to hardware constraints, VR
The display data stored in the AM cannot be retained by a backup battery or the like, and therefore a personal computer cannot have a perfect resume function.

This invention is useful for personal computers that cannot directly back up display data stored in VRAM with a backup battery or the like due to hardware limitations.
The purpose of the present invention is to provide a display memory backup control method that can have a resume function.

[Structure of the Invention] (Means for Solving the Problems) The present invention provides a system that backs up the system memory and re-executes the program from the state immediately before the power was cut off when the main power is turned on again even if the main power is cut off. In a computer system having this function, there is a backup rectangular display memory in which display data is stored, a backup memory allocated to the system memory and in which a copy of the display data is stored, and an execution status for realizing the resume function. L. Just before the main power is turned off, the contents of the display memory are saved to the backup memory and the status memory is saved.) When the power is turned on again, the above save operation is confirmed and restored to the display memory. The present invention is characterized in that the status memory is reset to realize a resume function.

(Function) As described above, the present invention provides a VRA that stores display data.
M, a backup memory for storing display data of VRAM, a display data storage status memory for storing resume function data, and a bank-up battery for backing up the contents of the backup memory and display data storage status memory. , VRAI
A small device that realizes the resume function of VII.

Display data stored in VRAM cannot be directly backed up using a backup battery, etc. Even in internal converters, one display data can be backed up to a part of the backed up memory (VRAM itself can be backed up). It is possible to have the same function as the re-gime function.

(Example) Embodiments of the present invention will be described below using the drawings.

FIG. 1 is a block diagram showing an embodiment of the present invention. In the figure, reference numeral 1 is a CPU, which serves as the control center of the system. Code 2 is BIcis ROM, and CPU 1
A control program for controlling each control block to be described later is stored therein. BiO2ROM 2
consists of non-volatile memory and includes a resume control program. Reference numeral 3 is a system bus, which serves as a data bus for data exchange. Reference numeral 4 is a display data storage status memory, which is a memory in which status (information) for realizing a resume function is stored. The memory contents are retained by a backup battery 8, which will be described later.

Reference numeral 5 denotes a system memory, which is a memory in which application programs and the like are stored, and the memory contents are retained by a backup battery 8. Code 6 is VRAM
This is a memory in which display data is stored. code 7
is the display control circuit.

It controls the interface between the VRAM 6 and the display device t9 in order to display the display data stored in the VRAM 6 on the display device 9. The code 8 is a Buffalough" battery,
The contents stored in each memo IJ 4 , 5 , 51 are held (backed up). Reference numeral 5 denotes a backup memory, which is a part of the system memory 5 and is a memory in which data necessary for performing a backup backup is stored.

FIG. 2 is a flowchart showing the operation of the embodiment of the present invention, in which (at) shows the saving operation of VRAM display data, and FIG. 2 (b) shows the storing operation of display data to VRAM. In the figure, Reference numeral 21 is a step for saving display data, in which the display data stored in the VRAM 6 is stored in the backup memory 5. Reference numeral 22 is a step for setting the display data storage status memory 4. It is stored that the process of step 2 was performed.

Reference numeral 23 is a step for determining whether or not display data has been saved, and the contents of the display data storage status memory 4 are read out to determine whether or not the process of step 2 has been performed. Reference numeral 24 is a step of storing the display data in the VRAM 6, and the display data saved in step 2 is returned to the VRAM 6. Reference numeral 25 is a step for resetting the display data storage status memory 4.

Now, the backup memory 5 is a part of the system memory 5 and is allocated in advance for backup purposes. This writing/reading of data into the memory 51 is performed by a resume control program built into the BiO2ROM 2. This cannot be done by a computer user or an application program. The display button storage status memory 4 is a memory for identifying whether or not resume control has been performed.

The data stored in the memories 4 and 51 is backed up by a knock-up battery 8, and the data contents are retained even if the main power of the computer is turned off.

Next, the operation of the embodiment of the present invention will be explained using the flowchart shown in the second diagram. Figure 2 [a] of the housing shows how the display data is deleted when the main power of the computer is turned off.
It is a flowchart which shows the operation|movement of l/L'-chi/. The display data saving routine shown in FIG. 2(a) is BiO2
This is done by the resume @j program in ROM2. When the routine shown in FIG. 2(a) is started,
The display data in the VRAM 6 is read out and saved in the backup memory 51 (step 21). next,
In order to remember that the operation of step 21 has been performed, the contents of the 5 display data storage status memory 4 are set (step 22). If this operation is performed, the main power of the computer will be turned off.

The operation of the display data restore routine that is carried out at step 7c after the main power of the computer is turned on again is shown in the flowchart of Figure 2 (b). The routine shown in FIG. 2(b) is also executed by the resume control program.

When the routine shown in FIG. 2(b) is started, the CPU
1 reads out the contents of the display data storage status memory 4 and determines whether or not the process of step 21 has been performed (Stella f23). If the process in step 2 has not been performed, nothing is performed as resume control. When the Stella f21 process is being performed, the CPU J reads the display data stored by the Stella f21 from the backup memory 51 and stores it in the VRAM 6. When this operation is performed, in order to start the routine shown in FIG. 2(a) next time, the CPU 1 changes the state of the display data storage status memory 4 so that the routine shown in FIG. 2(a) is not performed. Return to state (reset). This allows VRAM
The state at 6 returns to the state before the routine start in FIG. 2 (at).

In the embodiment of the present invention, only the backup of display data in VRAM has been described, but the present invention can be similarly applied to backup of other control memories.

9- [Effects of the Invention] As explained above, according to the present invention, display data stored in VRAM can be saved to a part of the backed-up memory even in a personal computer that cannot be directly backed up with a backup battery or the like. By doing so, it is possible to provide the same function as backing up the VRAM itself and realize resume control.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing an embodiment of the present invention, and FIG. 2 is a flow chart showing the operation of the embodiment of the present invention. 1... CPU, 2... BiO2ROM, 4... Display data storage status memory, 5... System memo IJ, 51... Backup memory, 6... VR
AM (display memory), 8... Backup battery. Takehiko Suzue, Patent Attorney, Isameto 10- Main power on, main power off (a) Return to the state before the first startup (b) Figure

Claims (1)

[Claims] In a computer system in which the system memory is backed up and has a resume function that re-executes the program from the state immediately before the power was turned off when the main power is turned off and turned on again, the display memory that cannot be backed up and stores display data, and the above-mentioned system A backup memory allocated to the memory and storing a copy of the display data, and a status memory storing an execution status indicating that the contents of the display memory are saved in the backup memory. , save the contents of the display memory to the backup memory and set the status memory immediately before the main power is turned off, and when the power is turned on again, refer to the status memory to confirm the save operation and save the contents of the display memory to the backup memory. A display memory backup control method characterized in that the contents of the display memory are restored to the display memory and the status memory is reset to realize a resume function.