JPH06195527A - Ic memory card - Google Patents

Abstract

PURPOSE:To effectively utilize a semiconductor memory and its address space by providing an IC for control with memory map registers which can freely set a memory map. CONSTITUTION:When an address signal is inputted from outside and an address is stored in an address register 11, comparing means 16-19 compare the address with respective final addresses stored in memory map registers 12-15 and an address arithmetic unit 24 determines and outputs an address of a semiconductor memory to be selected according to the comparison results. Therefore, the memory map registers 12-15 capable of freely setting the memory map store the final addresses of respective semiconductor memories and those final address and external input address are compared to effectively determine the address of the semiconductor memory to be selected.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor memory and an IC memory card which enables effective use of its address space.

[0002]

2. Description of the Related Art FIG. 7 is a diagram showing an address configuration of a conventional IC memory card. In FIG. 7, 1 is an IC memory card, 2 is a control IC provided in the IC memory card 1, and 3 to 6 have their address terminals 3a to 6a connected to the address control terminal A of the control IC 2, CE bar terminals 3b to 6b are semiconductor memories connected to CE bar control terminals CE1 to CE4 of the control IC 2, respectively. These semiconductor memories include SRAM, OTP
There are several types such as ROM, EEPROM, and MASKROM.

The conventional IC memory card 1 is constructed as described above, and the addresses of the semiconductor memories 2 to 6 are controlled by the control IC 2. Also, control IC
The address space corresponding to the two CE bar control terminals CE1 bar to CE4 bar is predetermined. FIG. 8 is a diagram showing a case where one address space is 2 Mbytes, and FIG. 9 is a diagram showing a state where two 2 Mbyte mask ROMs and two 64 Kbyte EEPROMs are connected.

[0004]

However, in such a conventional IC memory card, the CE bar control terminal C is used.
Since the address area is defined for each of E1 to CE4 bars, a semiconductor memory having a small capacity as shown in FIG. 9 (for example, 64 Kbytes EEPR for 2 Mbytes)
When the OM) is connected, there is a problem in that there are vacant addresses as indicated by 9a and 9b, and effective use of that address space cannot be achieved.

The present invention has been made to solve the above-mentioned problems, and an object thereof is to provide an IC memory card which can effectively utilize a semiconductor memory and its address space.

[0006]

An IC memory card according to a first aspect of the present invention is a control IC provided with a memory map register capable of freely setting a memory map.

In the IC memory card according to claim 2 of the present invention, the control IC is provided with a memory map register capable of freely setting a memory map, and the memory map data is temporarily stored in the semiconductor memory. After
The memory map register is loaded.

Further, in the IC memory card according to claim 3 of the present invention, the control IC is provided with a memory map register capable of freely setting a memory map, and based on the value of the memory map register, the external Judge whether the memory of the address input from is being used, and if the memory of the above address is not used, determine the means for outputting to the outside that the memory of this address is not used. It is provided.

[0009]

According to the IC memory card of claim 1 of the present invention, the final address of each semiconductor memory is stored by the memory map register capable of freely setting the memory map, and the final address and the external address are input. The address of the semiconductor memory to be selected can be effectively determined by comparing the address with the selected address.

Further, according to the IC memory card of claim 2 of the present invention, when the memory map data is stored in the memory map register, the memory map data is stored in the semiconductor memory in advance from the outside. The memory map data can be loaded from the semiconductor memory when the memory card is used for the first time.

Further, according to the IC memory card of the third aspect of the present invention, an unused address can be used for connecting the external control device.

[0012]

【Example】

Example 1. Embodiment 1 of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing a configuration of address control of a control IC. In FIG. 1, 11 is an address register that is connected to an external signal line S and temporarily stores an address input from the outside, 12 to 15 are memory map registers that store the final addresses of the semiconductor memories 3 to 6, 16 ˜19 are comparison means for comparing the contents of the address register 11 and the memory map registers 12-15, respectively, 20-23 are NAND circuits connected to the comparison means 16-19, and the NAND circuit 20 is for the comparison circuits 16-19. The output is directly input, and the NAND circuit 21 is compared by the comparison means 16 to.
The output of 18 is directly input, the inverted output of the comparison means 19 is input, the output of the comparison means 16 and 17 is directly input to the NAND circuit 22, and the inverted outputs of the comparison means 18 and 19 are input to the NAND circuit. 23, the output of the comparing means 16 is directly input, and the inverted outputs of the comparing means 17 to 19 are input. Further, 24 is an address register 11, memory map registers 12 to 15, and NAND circuits 20 to 23.
Is an address operation device for calculating the real address of the semiconductor memories 3 to 6 connected to the output side of the.

FIG. 2 is a block diagram showing the configuration of the address arithmetic unit 24 in order to clearly show the processing of the address arithmetic unit 24. In FIG. 2, 25 is an AND circuit to which the inverted signal of the CE1 bar signal and the address signal are input, 26 is an AND circuit to which the inverted signal of the CE2 bar signal and the signal of the memory map register 12 are input, and 27 is C
An AND circuit to which the inverted signal of the E3 bar signal and the signal of the memory map register 13 are input, 28 is an AND circuit to which the inverted signal of the CE4 bar signal and the signal of the memory map register 14 are input, and 29 is its three inputs An OR circuit whose output terminals of AND circuits 26 to 28 are connected to the terminals, 30
Is a real address calculator, and 31 is an OR circuit whose two input terminals are connected to the output terminal of the AND circuit 25 and the output side of the real address calculator 30.

The operation of the first embodiment will be described below.
In FIG. 1, it is assumed that the memory map registers 12 to 15 now contain the final addresses of the semiconductor memories 3 to 6 connected to the CE1 bar control terminal to the CE4 bar control terminal, respectively. Here, when an address signal is input from the outside and the address is stored in the address register 11,
This address and each final address stored in the memory map registers 12 to 15 are compared by the comparing means 16 to 19, and the address arithmetic unit 24 selects the addresses of the semiconductor memories 3 to 6 selected based on the comparison result. Determine and output.

In this address determination, for example, in FIG. 2, when the CE1 bar control terminal is selected, the value of the address register 11 is directly output as the determined value, and C
When the E2 bar control terminal is selected, the value obtained by adding 1 to the difference between the value of the address register 11 and the memory map register 12 is determined as the actual address of the memories 3 to 6 and output. The same applies when the CE3 bar control terminal and the CE4 bar control terminal are selected.

Address register value-memory map register (X-1) +1 (X is the memory map register number)

The value determined by is determined and output as the real address of the semiconductor memories 3-6. The first embodiment is applied regardless of the number of digits (bit number) of an address input from the outside, the number of CE bar control terminals, and the number of digits of the address register 11 and the memory map registers 12 to 15.

Therefore, according to the first embodiment, the final address of each semiconductor memory is stored by the memory map register capable of freely setting the memory map, and this final address is compared with the address input from the outside. As a result, the address of the semiconductor memory to be selected can be effectively determined. Furthermore, one control IC can support various types of memory maps, and the development time of the IC memory card can be shortened.

Example 2. Embodiment 2 of the present invention will be described below with reference to the drawings. FIG. 3 is a block diagram for explaining a method of loading memory map data in the memory map register, and FIG. 4 is a block diagram for explaining FIG. 3 in more detail. FIG. 5 shows a memory map of a semiconductor memory for temporarily storing memory map data. In each figure, the same reference numerals as those in FIG. 1 indicate the same objects. 2A is a control IC, and 32 is a memory map register provided in the control IC 2A.
Corresponds to ~ 15. Reference numeral 33 is a semiconductor memory, which corresponds to 3 to 6 in FIG. Reference numeral 34 is a comparison means, which corresponds to 16 to 19 in FIG.

The operation of the second embodiment will be described below.
There are two types of semiconductor memory 33 of the IC memory card: common memory (normal memory) and attribute memory (memory in which the attributes of the IC memory card are recorded). In FIG. 4, since the memory map registers 12 to 15 of the control IC 2A have not been touched since the IC was shipped, the contents of the memory map registers 12 to 15 such as EEPROM and OTPROM are all FFFFFFH.
Has become. Therefore, the memory map registers 12 to 1
If the contents of 5 are all FFFFFFH, the CE1 bar is selected, and the address and data externally input are directly input to the semiconductor memory 33. At this time, the memory map data is input to the memory 33 as shown in FIG. After that, when the signal WP is set to the high level, the control I
C separates the address bus and data bus from the outside,
The memory map data is loaded from the memory 33. When the loading of the data is completed, the signal WP is set to the low level and the address bus and the data bus from the outside are connected again to return to the original state.

Therefore, according to the second embodiment, after temporarily storing the memory map data in the semiconductor memory in the IC memory card, when the IC memory card is used for the first time, this memory map data is transferred from the semiconductor memory to the memory map register. By loading, you can easily set the memory map.

Example 3. The third embodiment of the present invention will be described below with reference to the drawings. FIG. 6 is a block diagram for explaining a method of notifying an address of a semiconductor memory which is not used outside and controlling a control device (not shown) connected to the outside. In the figure, the same symbols as those in FIG. 1 indicate the same objects. 35 is a comparison means 1 on the input side.
9 is an external device control circuit connected to the external device 9 and having an output side connected to an external control device. Reference numeral 36 denotes a control signal of the control device, and 37 denotes an output signal from the comparison means 19 to the external control circuit 35.

The operation of the third embodiment will be described below.
In FIG. 6, when an address signal is input from the outside and the value is stored in the address register 11, the comparing means 1
The value stored in the address register 11 by 9 is compared with the value in the memory map register 15. When the value of the address register 11 is larger than the value of the memory map register 15, the comparing means 19 causes the external control circuit 35 to
A signal 37 is output to inform that the address is an empty address. External control circuit 3 receiving this signal 37
5 is a control signal 36 to a control device connected to the outside.
Is output.

Therefore, according to the third embodiment, since the control signal is output from the IC memory card to the unused address space to control the externally connected control device, the address space of the IC memory card is controlled. Can be effectively utilized. Incidentally, in the third embodiment, the address register 11, the memory map register 15, and the external control circuit 35 constitute the judging means of claim 3.

[0025]

As described above, in the IC memory card according to claim 1 of the present invention, since the memory map register capable of freely setting the memory map is provided in the control IC, the address of the semiconductor memory to be selected. Can be effectively determined. Further, one control IC can cope with various kinds of memory maps, and the development time of the IC memory card can be shortened.

The IC memory card according to claim 2 of the present invention is the IC memory card according to claim 2 of the present invention, in which a memory map register capable of freely setting a memory map is provided in the control IC. Since the memory map data is provided and temporarily stored in the semiconductor memory and then loaded into the memory map register, the memory map can be easily set in addition to the above effects.

Further, in the IC memory card according to claim 3 of the present invention, the control IC is provided with a memory map register capable of freely setting a memory map, and based on the value of the memory map register, the external Judge whether the memory of the address input from is being used,
When the memory of the above address is not used, the determination means for outputting to the outside that the memory of this address is not used is provided, so that the address space of the IC memory card can be effectively utilized. Has the effect.

[Brief description of drawings]

FIG. 1 is a block diagram showing a first embodiment of the present invention.

FIG. 2 is a block diagram showing an address calculation device.

FIG. 3 is a block diagram illustrating a method for loading memory map data into a memory map register.

FIG. 4 is a block diagram for explaining FIG. 3 in more detail.

FIG. 5 is a diagram showing a memory map of a semiconductor memory for temporarily storing memory map data.

FIG. 6 is a block diagram for explaining a method of controlling a control device connected to the outside.

FIG. 7 is a diagram showing an address configuration of a conventional IC memory card.

FIG. 8 is a diagram showing a case where one address space is 2 Mbytes.

FIG. 9 is a diagram showing a state in which two 2M-byte mask ROMs and two 64K-byte EEPROMs are connected.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 IC memory card 2A Control IC 3-6 Semiconductor memory 11 Address register 12-15, 12A-15A, Memory map register 16-19 Comparison means 24 Address operation device 32 Memory map register 33 Semiconductor memory 34 Comparison means 35 External control circuit

Claims (3)

[Claims] 1. An IC memory card including a control IC and a semiconductor memory, wherein the control IC is provided with a memory map register capable of freely setting a memory map. Memory card. 2. An IC memory card including a control IC and a semiconductor memory, wherein the control IC is provided with a memory map register capable of freely setting a memory map, and the memory map data is stored in the semiconductor memory. An IC memory card, characterized in that it is temporarily stored in a memory and then loaded into the memory map register. 3. An IC memory card having a control IC and a semiconductor memory, wherein the control IC is provided with a memory map register capable of freely setting a memory map, and the value of the memory map register is set. Based on the above, it is determined whether the memory of the address input from the outside is used, and if the memory of the above address is not used, it is output to the outside that the memory of this address is not used. An IC memory card provided with a determination means for