JPS62254249A - Reading system for card memory capacity - Google Patents

Abstract

PURPOSE:To recognize the memory capacity just by designating the read of the memory capacity information on a setting means after adding said setting means for memory capacity information to a memory card containing the memory of optional capacity. CONSTITUTION:A card using device 30 transfers a control command to a control circuit 18 in a memory card 10 via a control bus 32 to designate the read of data given from a memory capacity setting circuit 17. The transferred control command is decoded. When said command designates the reading of the data on a memory 11 received from the circuit 17, the circuit 18 reads out the read control signal and outputs it to the circuit 17 via a control line 21. The circuit 17 outputs the memory capacity information on the memory 11 onto a data bus 31. Then the device 30 reads the memory capacity information on the memory 11 of a memory card 10 out of the bus 31. Thus the memory capacity of the card 10 is correctly recognized.

Description

[Detailed Description of the Invention] [Object of the Invention] (Industrial Application Field) This invention provides a method for a card using device to recognize the storage capacity (card storage capacity) of a memory installed in a memory card, IC card, etc. The present invention relates to a preferred storage capacity information system.

(Prior Art) In recent years, so-called memory cards and IC cards have appeared in which integrated circuit components such as memory are mounted on business card-sized plastic cards. In particular, memory cards have become useful as portable storage media similar to floppy disks and the like.

Now, the storage capacity of the memory mounted on a memory card (storage capacity per card) varies depending on the number of memory elements (memory chips) constituting the memory and the storage capacity of the memory elements. If the storage capacity of this type of memory card (the memory inside it) is not constant, it may be difficult for a device (card usage bag) that uses this memory card as a storage medium to access the memory inside the card correctly. Become. Conventionally, one of two methods has been applied: a first method in which the card's storage capacity is notified to the card-using device through an operator operation, and a second method in which this device limits the cards that can be used to only memory cards with a predetermined storage capacity. was.

However, the first method not only increases the burden on the operator, but also has the problem that if an operational error occurs, the memory within the card cannot be accessed correctly. Although the second method does not have the above-mentioned problems, it has the problem of poor expandability because the capacity of the applicable memory card is limited to one type.

(Problems to be Solved by the Invention) As described above, conventionally, when the storage capacity of a card that can be used as an external storage medium is not limited to one type, the storage capacity of the card used can be adjusted by the operator's operation. had to be notified.

This invention has been made in view of the above circumstances, and its purpose is to provide a card storage capacity reading method that allows a card using device to recognize the storage capacity of a memory mounted on a card without operator operation. .

[Structure of the invention] (Means and effects for solving the problem) In this invention,
Storage capacity setting means for presetting storage capacity information indicating the storage capacity of the memory (card storage capacity) in a module mounted on the card and including a memory composed of one or more memory elements; and a control means. and is provided.

If the card usage "l1ItIl" needs to recognize the card storage capacity, it gives an instruction to the control means in the card to read out the storage capacity.If the instruction from the card usage device is an instruction to read the storage capacity, the control The means controls the output of the setting contents of the storage capacity setting means.This allows the card using device to read the storage capacity information set in the storage capacity setting means.

(Embodiment) FIG. 1 is a block diagram showing an embodiment of the present invention. In the figure, 10 is a memory card, and 30 is a device (card usage bag W) that uses the memory card 10.

31 is a data bus used for data transfer between the memory card 10 and the card use bag W130, and 32 is a control bus used to control the card use bag [30].

In the memory card 10, 11 is a memory, 12-1~
12-n is a memory element constituting the memory 11; The memory elements 12-1 to 12-n are, for example, RAMs. 1
3 is the memory data bus of the memory 11, 14 is the memory 11
An address bus 15 is an address counter that specifies the address of the memory 11. Address counter 15 is connected to address bus 14 and data bus 31.

16 is a bidirectional gate circuit that performs data input/output between the memory data bus 13 and the data bus 31; 17 is a memory in which storage capacity information indicating the storage capacity [1 (card storage capacity) of the memory 11 is set in advance]; This is a capacity setting circuit. The output of the storage capacity setting circuit 17 is connected to the data bus 31. Reference numeral 18 denotes a control circuit that controls various parts within the memory card 10. The control circuit 18 controls the memory 11 (memory elements 12-1 to 12-n therein) according to the control command given from the card user@@30 via the control bus 32.
It performs read/1 write control for the address counter 15, write (start address setting) and count-up control for the address counter 15, gate control for the gate circuit 16, read ilJ tll for the storage capacity setting circuit 17, and the like.

19 is a read/write control line mainly used for read/write control of the memory 11; 20 is an address counter 1;
A write control line 5 is used for write (start address setting) control, and a read control line 21 is used for read control of the storage capacity setting circuit 17.

The read/I write control line 19 includes memory elements 12-1 to 12-1.
12-n, address counter 15, gate circuit 16 and control circuit 18 are connected. Also, write control line 2
0 is connected to an address counter 15 and a control circuit 18, and a read control line 21 is connected to a storage capacity setting circuit 17 and a control circuit 18.

Next, the operation of one embodiment of the present invention will be explained.

When using the memory card 10 as an external storage medium, the card usage device 30 needs to recognize the storage capacity of the memory card 10 (the memory 11 therein). This recognition is realized by the card usage device 30 reading the storage capacity information set in the storage capacity setting circuit 11 in the memory card 10 via the data bus 31. In order to read this storage capacity information, the card using device 30 first sends a control command that specifies reading data from the storage capacity setting circuit 11 (more specifically, device specification information that specifies the storage capacity setting circuit 17). and a control command having read specification information specifying data read) is transferred to the υ11tG circuit 18 in the memory card 10 via the control bus 32.

When the control circuit 18 receives a control command transferred from the card usage device 30, it decodes the command. When the control command from the card usage device 30 specifies data reading from the storage capacity setting circuit 17, the control circuit 18 outputs a read Ill Ill signal to the storage capacity setting circuit 1γ via the read control line 21.

The memory write l setting circuit 17 outputs its setting information, that is, storage capacity information, onto the data bus 31 in response to a read control signal on the read control l line 21.

The card using device 30 can correctly recognize the storage capacity of the memory card 10 (memory 11 therein) by reading the storage capacity information output from the memory write setting circuit 17 from the data bus 31. That is, according to this embodiment, the card-using device! 30 simply transfers a control command specifying reading of data (reading of storage capacity information) from the storage capacity setting circuit 17 to the memory card 10 via the control bus 32 and captures the data on the corresponding data bus 31. The storage capacity of the memory card 10 (the memory 11 therein) can be recognized. Moreover, the control bus 32 used for specifying readout of storage capacity information and the data bus 31 used for transferring storage information are originally necessary for the card using device 30 to use the memory card 10 as a storage medium. Therefore, this embodiment does not require a special signal line for recognizing the storage capacity.

When the card usage device 30 recognizes the memory writing of the memory card 10, the card usage device 30 recognizes the memory card 10 within the range of its storage capacity.
Writing/reading to/from memory 11 within the memory 11 is performed at any time. Writing to the memory 11 will be briefly explained. First, the card using device 30 receives data (start address) for the address counter 15! A control command specifying writing is output onto the control bus 32, and data (start address) to be written (to be set) in the address counter 15 is output onto the data bus 31. The control circuit 18 decodes the control command on the control bus 32 and outputs a write control signal to the address counter 15 via the write control line Il 20.

As a result, the data being output from the card using device 30 onto the data bus 31 is set to the address counter 15 as the start address for accessing the memory 11.
be tested. The address specified by the address counter 15 is transmitted to the memory elements 12-1 to 12 via the address bus 14.
−n. In this embodiment, the upper m bits of the address specified by the address counter 15 (where m is an integer satisfying n-2'') are the memory elements 12-1 to 12-1.
12-n, and the remaining bits are used to address memory elements 12-1 to 12-n.

Next, the card using device 130 outputs a control command specifying data writing to the memory 11 (memory elements 12-1 to 12-n therein) onto the control bus 32, and outputs write data onto the data bus 31. The control circuit 18 decodes the control command on the control bus 32 and controls writing to the memory 11 via the read/I write control line 19, and the data on the data bus 31 is transferred onto the memory data bus 13. The gate circuit 16 is controlled as follows.

As a result, the data being output from the card using device 30 onto the data bus 31 is guided onto the memory data bus 13 via the gate circuit 16 and written to the address location in the memory 11 specified by the address counter 15. At this time, the address counter 15
The count is counted up under the control of the control circuit 18 via the control circuit 9, and the next write address is specified. As a result, writing to the memory 11 in the memory card 10 is performed sequentially. Note that data reading from the memory 11 in the memory card 10 is performed in the same manner as the above writing.

The above describes the recognition of the storage capacity of the memory in the memory card, but this invention
The same applies to recognition of the storage capacity of the memory in the card.

[Effects of the Invention] As detailed above, according to the present invention, the card usage device can simply specify readout of memory status information for a card equipped with a memory of an arbitrary storage capacity, and read out the memory status information stored in the card. Since it becomes possible to read the storage capacity information preset in the storage capacity information setting means, the card storage capacity can be recognized reliably without operator operation.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing an embodiment of the present invention. 10...Memory card, 11...Memory, 12-1
~12-n...Memory element, 17...Storage capacity setting circuit, 18...Control circuit, 30...Card using device, 31...Data bus, 32...Control bus.

Claims (2)

[Claims] (1) A storage capacity setting means for presetting storage capacity information indicating the storage capacity of the memory in a module mounted on the card that includes a memory composed of one or more memory elements; and a card using device. control means for determining the instruction contents from the card and controlling the output of the setting contents of the storage capacity setting means when storage capacity reading is instructed; By giving a memory capacity read instruction from
A card storage capacity reading method characterized in that the storage capacity information is read from the storage capacity setting means in the card. (2) The output of the storage capacity setting means is connected to a data bus for data transfer between the module and the card-using device, and the card-using device transfers the storage capacity to the storage capacity via this data bus. A card storage capacity reading method according to claim 1, characterized in that information is read.