JPS6258353A - Test method for on-line memory - Google Patents

Abstract

PURPOSE:To put an on-line memory to the test without discontinuing DMA transfer in an off-line mode by carrying out successively the memory tests first at and after the cells which are not under DMA transfer and then the memory cells under DMA transfer. CONSTITUTION:In a DMA transfer mode the memory cells having the DSW which are not under DMA transfer are selected and the DMA transfer mode is displayed to the buffer status word BSW. Then the DMA transfer is carried out and the display of the DMA transfer is erased when the DMA transfer is over. In a memory test mode a memory test mode is displayed after confirming that no DMA transfer is carried out within the BSW. Then the display of the memory test mode is erased when the memory test is over. In case any memory cell which is under the DMA transfer is detected, the test is put to the next memory cell after the DMA transfer is through with the first cell.

Description

[Detailed Description of the Invention] [Summary] A method for testing the memory of a system operating online, in which the operating memory is divided into a plurality of cells in advance, and inside each cell there is a signal indicating that the cell is undergoing DMA transfer. If you want to perform a memory test, select one of the cells that is not undergoing DMA transfer and perform the test, and when you find a memory cell that is undergoing DMA transfer. This makes it possible to defer that memory cell and test the next memory cell, making it possible to perform a memory test without stopping DMA transfer.

[Industrial application field]

The present invention relates to an online memory testing method, and more specifically, the present invention relates to an online memory testing method, and more specifically, the present invention relates to an online memory testing method.
This relates to a method of testing when performing ry Access) transfer.

[Conventional technology]

When testing the memory of an operating device, the memory is tested by masking interrupts in areas where DMA transfer is not performed. That is, by masking, it is possible to save the original contents and perform a write/continue test of arbitrary data, and then restore the saved original contents to perform a memory test.

[Problem that the invention seeks to solve]

However, in the area used for DMA transfer, DMA transfer is performed even if interrupts are masked, so the content transferred from memory may be destroyed or the test may fail depending on the content transferred to memory. This problem made it impossible to conduct an online memory test.

The present invention was created in view of these points.
In a system running online, the internal memory can be tested without stopping DMA transfer.
It aims to provide an online memory testing method.

[Means for solving problems]

FIG. 1 is a block diagram of the principle of the online memory testing method of the present invention.

As shown in FIG. 1, in the present invention, for example, the memory is composed of cells la, Ib, -.l
e.

Divide into 1fZ, write the address of the next cell in one address of each memory cell, and write the address of the next cell sequentially like this.
Let's make it ueue form. Information indicating whether DMA transfer is in progress and whether a memory test is in progress is entered into these memory cells. Below, this is called BSW (Buff
er 5tatus Word). When performing a memory test, it is confirmed that DMA transfer within the BSW is not in progress, a memory test in progress display is displayed and the test is performed, and when the memory test in progress display is erased. If a memory cell undergoing DMA transfer is found, that memory cell is postponed and the next memory cell is tested, or the process is stopped for a certain period of time and then tried again after the lapse of time. Of course, the size and connection state of the memory cells are not limited to those described above.

[For production]

In the present invention, memory tests are performed sequentially starting from cells that are not undergoing DMA transfer, and memory cells that are undergoing DMA transfer are tested later, so the DMA test is performed offline.
Online memory tests can be performed without stopping the transfer.

〔Example〕

FIG. 2 shows an embodiment of the present invention, in which the memory cell in FIG. 1 has a Queue information area 2 and a BSW storage area 3, and the SSW area is a RAM test display area 3a and a DMA transfer display area. 3b is included.

In the structure shown in Figure 2, when performing DMA transfer, select a memory cell whose DSW is not undergoing a memory test,
DMA after displaying that DMA transfer is in progress to BSW
The transfer is performed, and when the transfer is completed, the display indicating that the DMA transfer is in progress is erased. When performing a memory test, it is confirmed that DMA transfer within the BSW is not in progress, a memory test in progress display is displayed, the memory test is performed, and when the memory test is completed, the memory test in progress display is turned off. If a memory cell undergoing DMA transfer is found, the next memory cell is tested after waiting for the DMA transfer of that memory cell to be completed.

FIG. 3 is an operational flowchart of the present invention.

First, when the first memory cell is acquired in block 11, it is checked in block 12 whether DMA transfer is in progress.

If it is found in block 12 that DMA transfer is in progress, timing is set in block 13 and a time wait is performed, and if DMA transfer is not in progress, block 14
An interrupt mask is set in block 15, a write/continue test is performed in block 15, and the result is determined in block 16. Whether the judgment result is G or NG
The interrupt mask is stored in blocks 17 and 18 respectively, and the interrupt mask is reset in block 19. In block 20, the same test is repeated if there is a next memory block, and if there is not, the test is repeated. end. The test result is determined by the G and NG information stored in blocks 17 and 18.

〔Effect of the invention〕

As described above, according to the present invention, there is no need to take an online system offline for memory testing, a quick and reliable test method is provided, and it is extremely useful in practice. be.

[Brief explanation of drawings]

FIG. 1 is a block diagram of the principle of the online testing method according to the present invention, FIG. 2 is a diagram explaining the present invention in detail, and FIG. 3 is a flowchart of the operation of the present invention. 1 and 2, 1a to 1f are memory cells, 2 is a queue information storage area, 3 is a buffer status word, 3a is a RAM test in progress display, and 3b is a DMA transfer in progress display. Block diagram of the principle of the present invention Detailed explanation of the present invention Figure 2

Claims (1)

[Claims] In an online memory test method that tests the memory of a system that operates online during DMA transfer, the operating memory is divided in advance into a plurality of cells (1a to 1f), and inside each cell there is a Displays the information (3b) indicating whether the memory is present or not, and the information (3a) indicating whether the memory is being tested or not. When performing DMA transfer, select one of the cells that is not undergoing a memory test, and transfer the DMA to that cell.
When performing a DMA transfer by displaying that MA transfer is in progress (3b) and performing a memory test, the DMA
An online memory test method characterized in that a memory test is performed by selecting a cell that is not being transferred, displaying (3a) on the selected cell that it is undergoing a memory test.