JPH03269785A - Contact failure detecting method for memory card - Google Patents

Abstract

PURPOSE:To prevent the malfunction in advance by sending out successively a prescribed address signal and data to an address line and a data line of a memory card writing the data, and thereafter, reading it. CONSTITUTION:When a memory card 1 is installed in a device 2, a contact failure detecting part 3-1 inputs successively an address signal by which only one piece of address lines of the installed memory card 1 becomes '1' (or '0') and writes data, and thereafter, when read data does not match with written data, it is detected to be a contact failure. Also, data 55H (and AAH) are inputted to a data line and written, and thereafter, when read data does not match with these written data, it is detected to be a contact failure. In such a way, the contact failure of the memory card 1 can be detected simply and exactly by a software, and a data change and a runaway of a program can be prevented in advance.

Description

[Detailed Description of the Invention] [Summary] A contact failure detection method for detecting contact failure when a memory card is installed in a device includes sequentially sending predetermined address signals and data to the address line and data line of the memory card. A memory card with multiple address lines and multiple data lines is installed in a device with the purpose of detecting poor contact by reading after writing and preventing malfunction by detecting poor contact of the memory card. Sometimes, after writing data by sequentially inputting address signals in which only one of the address lines of this memory card becomes 1 (or O) from the device, the read data does not match the written data. A contact failure is detected, and a contact failure is further detected when the data read after inputting and writing data 55H (and AAH) to the data line does not match the written data.

[Industrial application field]

The present invention relates to a contact failure detection method for detecting contact failure when a memory card is installed in a device. In recent years, memory cards have rapidly become popular with the development of semiconductor technology. Along with this, it has become possible to easily attach and detach memory cards (extended RAM cards, etc.) to personal computers and word processors. At this time, it is desired to easily detect poor contact of the memory card using software.

[Prior art and the problem to be solved by the invention] Conventionally, when a memory card is inserted into an expansion slot of a personal computer or word processor, the insertion is determined by checking that the pins at both ends of the memory card are in contact. was. For this reason, there is a problem in that even if a contact failure occurs, such as when the memory card is installed at an angle in the device or when dust gets caught, it cannot be detected.

In addition, if the memory card is a ROM, there is a method of writing a checksum on the memory card in advance and reading it with software to detect poor contact in advance. The problem was that I couldn't leave it there.

The present invention sequentially sends predetermined address signals and data to address lines and data lines of a memory card, writes them, and then reads them to detect poor contact, thereby detecting poor contact of the memory card and preventing malfunctions. It is intended to.

[Means to solve problems]

Means for solving the problem will be explained with reference to FIG.

In FIG. 1, a memory card 1 is a readable/writable memory card having multiple address lines and multiple data lines.

The device 2 is to which the memory card 1 is attached.

The contact failure detection unit 3-1 is a program that detects contact failures in a plurality of address lines, a plurality of data lines, etc. of the memory card l.

[Effect]

As shown in FIG. 1, when the memory card 1 is installed in the device 2, the present invention detects that only one of the address lines of the installed memory card 1 is 1.
(or 0) and write data. If the read data does not match the written data, a contact failure is detected, and data 55H (and AAH) is input to the data line. A contact failure is detected when the data read after being written does not match the written data.

Therefore, by sequentially sending predetermined address signals and data to the address line and data line of the memory card 1, writing them, and then reading them to detect a contact failure, a contact failure of the memory card 1 can be detected and a malfunction can be prevented. This makes it possible to prevent

〔Example〕

Next, the 1st Tj! The configuration and operation of one embodiment of the present invention will be sequentially explained in detail using FIGS.

In FIG. 1, a memory card 1 is a readable/writable memory card having a plurality of address lines and a plurality of data lines, and is, for example, a RAM CARD.

The device 2 is a word processor, a personal computer, etc., whose memory capacity is expanded by attaching the memory card 1 to an expansion board, and includes a memory 3, a CPU 4, a display 5, and a keyboard 6.
, an FD (floppy disk device) 7, a printer 8, and the like.

The contact failure detection unit 3-1 is a program that detects contact failures in a plurality of address lines, a plurality of data lines, etc. of the memory card l.

FIG. 2 shows an explanatory diagram of contact failure detection of a memory card according to the present invention, where the address oooooo is the address line (address bus) of the memory card 1 installed in the device 2.
represents the address signal input to the data 00.55, A
A represents data to be written to the data line (data bus) of the memory card l.

In Figure 2, the shaded area is data 00.55, AA
This is an area where you can write such things. These areas are at addresses 000001 (=2°) and 000002 (・21
), 000004 (・2”), 000008 (・2
3) Corresponding to..., this is an area where only the lower bits 1, 2, 3, etc. of the address line are set to 1 (described later using FIG. 5), and data 00H is stored in these areas. Data 55 (data AA) is read after writing to detect a contact failure in the address line (described later with reference to FIG. 3).
1 byte data of 1010101 (10101010
1 byte of data) is written all at once and then read to detect the contact of data &I (8 pin width data line) (described later using the 4th WJ).

The procedure for detecting contact failure of address lines will be explained in detail using the flowchart of FIG.

In FIG. 3, (■) attaches the memory card 1 to the device 2.

(2) detects whether the pins at both ends are inserted correctly. This is because when the memory card 1 is inserted into the expansion board of the device 2 in step (3), the hardware detects whether or not the bins at both ends of the memory card 1 have been correctly inserted. If YES (normal), contact failure detection is performed by software for 0 to [phase]. No
In this case, it is determined that there is a poor contact.

0 writes 0 to address 2°. This means that the contact failure detection unit 3-1 in FIG.
Input address e' and write data OOH.

■ writes 0 to address 21.

Similarly, 0 is sequentially written from address 22 to address 21.

■ writes 0 to address 215.

By the above procedure, data OOH is written to the address (shaded area in FIG. 2) where any bit of address lines 0 to 15 is set to 1.

[Phase] reads data from address 2°.

0 determines whether the data read in [phase] is 0 or not. If YES, it is determined that the address line at the 2° address is normal, and the next address line is selected using [Phase].
In this case, since the read data does not match the written data 0, it is determined that there is a contact failure.

[Phase] reads data from address 20.

[Phase] determines whether the data read in (■) is 0 or not. If YES, it is determined that the address line at address 21 is normal, and the next address line is determined. If NO, it is determined that there is a contact failure.

Similarly, addresses 22 to 21414 are sequentially read to determine whether they are 0 or not. If YES, it is determined to be normal, and if NO, it is determined to be poor contact.

[Phase] reads data at address 21515.

(2) determines whether the data read in [phase] is 0 or not. If YES, it is determined that the address line at the address 2+s is normal, and that all address lines 0 to 15 are in proper contact. On the other hand, in the case of NO, it is determined that there is a poor contact.

Next, the procedure for detecting poor contact of the data line will be explained in detail using the flowchart of FIG.

In FIG. 4, [phase] writes data 55H to the memory card 1. As shown in FIG. 5(b), data 55H of 01010101, in which 0 and 1 appear alternately, is sent to the data line of the memory card 1 and written. In addition, the bit width of the data line is not 8 pints, but 1 pin width.
If it is wide like 6 bits, 5555H is written all at once.

@ reads data from the memory card.

0 determines whether the data read at O is 55H. If YES, data AA in [phase] or [stock]
The same process is performed for H. If NO, it is determined that there is a poor contact in the data line.

[Phase] writes data AAH to the memory card 1. This is 1010102 as shown in Figure 5 (b).
Data AAH in which 0, 1 and 0 appear alternately, is sent to the data line of the memory card 1 and written. Note that if the focus width of the data line is not 8 bits but wider, such as 16 bits, AA AAH are written all at once.

■ Read data from the memory card.

[Stock] determines whether the data read in ■ is AAH or not. If YES, it is determined that the data line contact is normal. On the other hand, in the case of NO, it is determined that there is a poor contact of the data line.

FIG. 5 shows an explanatory diagram of address lines/data lines according to the present invention.

In Figure 5 (a), the address line is 2°, 21.22...
・Address 2° at 215, address 21, address 21...
The address signal of address 215 is shown. These are address signals when the focus is 1, and whether or not the address line corresponding to 1 is in contact is detected according to the procedure shown in the flowchart of FIG.

FIG. 5(b) shows data 55H and AAH written when the data lines are 2821, 22, . This is data in which "" and "O" appear alternately. The data 55H and AAH are used to detect whether or not the data line is in good contact according to the procedure shown in the flowchart of FIG.

〔Effect of the invention〕

As explained above, according to the present invention, the memory card 1
A predetermined address signal is sent to the address line of the
For example, OOH, etc.) is read after writing, and data 55H and AAH are written to the data line and then read to detect contact failures, so contact failures of memory cards can be detected easily and easily by software. Can be detected accurately. This makes it possible to detect poor contact with the memory card and prevent data corruption and program runaway.

[Brief explanation of drawings]

Fig. 1 is a schematic diagram of one embodiment of the present invention, Fig. 2 is an explanatory diagram of contact failure detection of a memory card according to the present invention, Figs. 3 and 4 are flowcharts for explaining the operation of the present invention, and Fig. 5 is An explanatory diagram of address lines/data lines according to the present invention is shown. In the figure, 1 represents a memory card, 2 represents a device for mounting the memory card, and 3-1 represents a poor contact detection unit.

Claims (1)

[Claims] In a poor contact detection method for detecting poor contact when a memory card is installed in a device, a memory card (1) having multiple address lines and multiple data lines is connected to a device (2).
), the device (2) sequentially inputs an address signal such that only one of the address lines of this memory card (1) becomes 1 (or 0), writes data, and then reads it. A contact failure is detected when the data does not match the written data, and a contact failure is detected when the data read after inputting and writing data 55H (and AAH) to the data line does not match the written data. A method for detecting poor contact of a memory card, characterized in that the method is configured to detect poor contact of a memory card.