WO2000014644A1

WO2000014644A1 - Multiple uses of pcmcia interfaces

Info

Publication number: WO2000014644A1
Application number: PCT/SE1999/001480
Authority: WO
Inventors: Jan Peter Mikael WICKSTRÖM; Håkan Erik WESTIN; Per Anders Hedberg
Original assignee: Telefonaktiebolaget Lm Ericsson (Publ)
Priority date: 1998-09-08
Filing date: 1999-08-27
Publication date: 2000-03-16
Also published as: AU6235299A

Abstract

According to an exemplary embodiment of the present invention a PC-card is provided that can be used in multiple-modes of operation. When the PC-card is connected to a PCMCIA interface, the PC-card will function according to the PCMCIA standard; however, when the PC-card is connected to a non-PCMCIA interface, the PC-card will switch modes of operation and operate according to the type of non-PCMCIA interface. According to an exemplary embodiment of the invention, the PC-card is provided with an ASIC for monitoring the connection of the PC-card to a computer slot or interface. According to embodiment if the card is connected to a non-PCMCIA interface the ASIC switches the card from PCMCIA standard mode of operation to an alternative mode of operation compatible with the type interface that the card is connected to. The card can be switched from the standard to non-standard modes of operation by detecting a combination of signals on the interface that are invalid under the standard mode of operation.

Description

MULTIPLE USES OF PCMCIA INTERFACES

BACKGROUND

The invention is related to computer interfacing and in particular multiple uses of PCMCIA cards with different types of interfaces. PCMCIA technology has made personal computing simpler than ever for computer users. PCMCIA technology allows users to easily install and interchange many different peripheral devices with computers. PCMCIA is an acronym for Personal Computer Memory Card International Associations and defines a standard for an interface for "plug-in" cards for Personal Computers. PCMCIA cards have become increasingly popular for use with personal computers, such as laptops, for many reasons.

PCMCIA cards or "PC-cards," as they have become known throughout industry, allow easy installation of peripheral devices by computer system users. In order to install the device the user simply plugs-in the PC-card in a slot connected to the host computer system. There is no need for screwdrivers, setting of switches, etc., as is often required when installing a new peripheral device in a computer system. Because PC-cards are a standard size, the same card slot can be used to accept a wide variety of devices, for example, storage cards, network cards, and fax/modems, etc. The PC-card also provides for flexibility, allowing the user to purchase options as needed, at any time, in order to customize the computer to their needs. Finally, the simplicity of the card reduces system maintenance costs as well as training and installation time.

On the other hand the same features that provide the above described benefits to users of PC-cards also prevents the PC-cards from being used in interfaces that do not conform to the PCMCIA interface standard. Because of the standard controlling the use of PC-cards, PC-cards are not able to be used in personal computers without PCMCIA interfaces and drivers. There are an increasing number of computer products would benefit from the functions available on PCMCIA cards but, due to the complexity of the PCMCIA interface, it is hard to implement the circuits needed to comply with the PCMCIA interface specification on these products, for any number of reasons.

For example, microprocessors are being installed in many devices today such as, phones, calculators, vending machines, etc. However, because of the complexity of the PCMCIA standard, being able to except any type of PC-Card, whether it be a modem or network interface, the adaptor and software required to make the device compatible with the PC-card can become cost and/or size prohibitive. However, without the proper PCMCIA standard interface, the card may not be used.

SUMMARY It is an object of the present invention to increase the versatility of PCMCIA cards. It is another object of the invention to allow PC-cards to be used with devices that are not provided with PCMCIA standard compatible interfaces.

According to an exemplary embodiment of the present invention the foregoing and other objects are accomplished through implementation of a PC- card that can be used in multiple-modes so that when the PC-card is connected to a PCMCIA interface, the PC-card will function according to the PCMCIA standard; however, when the PC-card is connected to a non-PCMCIA interface, the PC-card will switch modes of operation and operate according to the non-PCMCIA interface. According to an exemplary embodiment of the invention a PC-card is provided with an circuit for monitoring the connection of the PC-card to a computer slot or interface. According to this exemplary embodiment, if the card is connected to a non-PCMCIA interface the ASIC switches the card from a PCMCIA standard mode of operation to an alternative mode of operation compatible with the type interface that the PC-card is connected to. According to this embodiment the PC-card can be switched from the standard to non-standard modes of operation by detecting a combination of signals on the PC-card interface that are invalid under the standard mode of operation.

According to another exemplary embodiment of the invention a PC-card is provided with an adaptor for use of the PC-card, utilizing a second PC-card interface, for example a serial interface, when a PCMCIA interface is not available.

BRIEF DESCRIPTION OF THE DRAWINGS.

The foregoing and other features, objects, and advantages of the invention will be better understood by reading the following description in conjunction with the drawings, in which:

Fig. 1A illustrates an example of a PC-card for use with the PCMCIA standard;

Fig. IB is an illustration showing two PC-cards for use with a lap-top computer;

Fig. 2 is an exemplary computer system;

Fig. 3 is exemplary PC-Card and interface according to an embodiment of the invention; and

Figs. 4 A and 4B are exemplary embodiments illustrating a PC-Card and interface connected to different cord/adaptors.

DETAILED DESCRIPTION:

The various features of the invention will now be described with respect to the figures, in which like parts are identified with the same reference characters. Fig. 1A illustrates an example of a PCMCIA card 100 or "PC-Card." PC- cards provide various peripheral devices in a compact and user-friendly form. According to the PCMCIA standard PC-cards are categorized into three types of cards: type I, type π, and type DA. Type I cards typically provide storage devices such as battery backed Static Random Access Memory (SRAM), Read Only Memory (ROM), flash memory, Small Computer System Interface (SCSI). Type II cards feature various input and output (I/O) devices, for example, modems and LANs. Type III cards include advanced function I/O cards with additional features such as wireless modems, multimode cards (cards with more than one function, such as a combined modem and LAN card), and small hard drive storage. A typical PC-card 100 is about the size of a credit card and has a 68-pin connector 110 on one end. The cards are approximately all the same size and vary only in thickness, with type I cards being the smallest at about 3.3 millimeters thick and type III cards being the largest, at approximately 10.5 millimeters thick. The 68 pin connector 110 connects to the host computer when the card is placed into a "PC-card slot" capable of receiving the PC-card. For example, a laptop computer 130 as illustrated in Fig. IB supports two slots 103 for two PC-cards 101 and 102. Some PC-cards are also provided with an adapter 120 at one end, for example, a modem PC-card has an adapter for connecting with a phone line in order to send and receive information over a phone. Other cards, for example some memory cards, have no adapter.

Fig. 2 illustrates a typical computer system including a processor 250 (CPU) and memory 260 connected by a memory bus 265. This system is for exemplary purposes only and one of skill in the art would realize that other types of computer systems and configurations may also be used without departing from the scope and spirit of the invention.

In addition, a system bus 220 is provided which is operated by a bus controller 230 for communicating between the CPU and various devices connected to the system, such as a display 240 and input device 245 (e.g., a keyboard, mouse, touchscreen, etc.). According to the exemplary system shown in Fig. 2 a PC-card adapter 210 is provided for receiving a PC-card 100 in a PC-card slot 103. The adapter provides an interface for the PC-card and the software necessary to enable the PC-card to communicate with and utilize the system CPU 250 and memory 260 according to the PCMCIA standard. Conventionally, in order for a system to be able to interface with a PC-card, a PCMCIA adaptor with PCMCIA drivers must be provided or other dedicated software and interface must be provided. However, such an adaptor is not feasible, for example, because of cost or size prohibitions in many devices (e.g., a pocket calculator).

According to an exemplary embodiment of the present invention, as illustrated in Fig. 3 for example, a PC-card is provided with a pin connector 320. The connector 320 is a standard PCMCIA 68 pin interface capable of being inserted into a PC-card slot interface, which under the PCMCIA standard is a parallel interface. Also under the PCMCIA standard, one of the pins is provided with a card enable signal (C/E) 331. The C/E signal is activated when the PC- card is inserted into PC-card slot and the computer system is communicating with the card. In addition, two other signals are also provided, a write signal 332 and a read signal 333.

According to the PCMCIA standard, when the system bus 220 wants to write information from the bus 220 to a PC-card 100 the C/E and read signals are both enabled along with other pins needed to download the information from the system bus 220 to the adapter 210 and the PC-card. When the bus needs to read information from the PC-card the C/E and read signals are enabled, along with other pins on the PC-card, and the information is read from the PC-card and PC- card adapter and loaded onto the system bus. Under the PCMCIA standard there is never a situation when all three of the signals C/E, write, and read are enabled simultaneously.

According to one aspect of the invention, these signals, for example the C/E, write, and read, may be used to switch the PC-card between different functionalities or non-standard modes which depend on the type of interface 300 that is connected to the pin connector/interface of the PC-card. According to the exemplary embodiment of the invention illustrated in FIG. 3, a PC-card is provided with an ASIC for monitoring the signals appearing on the pin connector. When the PC-card is connected to a PCMCIA standard interface the PC-card will operate under the normal PCMCIA functionality. However, according to the present invention, the PC-card 104 may also be used with non-PCMCIA standard interfaces, such as serial interfaces (e.g., an RS-232 or UART type interface).

When the interface 300, is a non PCMCIA standard interface, the signals 331, 332, and 333 are all enabled. Since there is never a situation when all three of these signals are enabled when connected to a PCMCIA interface, the ASIC monitoring the pin connector recognizes that the card is connected to a non- PCMCIA standard interface. As a result the ASIC switches the PC-card to a non- standard mode. The remaining pins 330 can then be used to establish what type of interface the PC-card is connected with and proceed with communication in the non-standard mode. According to the present invention, when the PC-card is connected to a non-standard interface it is not necessary that all of the pins 330 be connected to the interface 300.

One possible method for identifying the type of interface is described hereafter. For example, the three select signals (i.e., read, write CIE) could be used together with four of the address signals. This arrangement provides 16 possible combinations that can be used to represent different types of interfaces that could be used for the non-standard interface. In addition, there is no requirement, according to this exemplary embodiment, that an adaptor be provided between the PC-card and the host environment. For example, the host electronics for the non-standard interface can be designed in conjunction with the specification of the non-standard AC-card interface.

Furthermore, one skilled in the art will recognize that other pins or signals could be used to place the PC-card into a non-standard mode. One skilled in the art will further appreciate that this exemplary embodiment could be used with any of the type I, II, or III PC-cards.

According to this exemplary arrangement, the PC-card is made significantly more flexible. According to the present invention, the card may be adapted to be used with virtually any type of interface, thereby allowing the card to be used with a large number of other computer devices that are not presently cable of communicating with PCMCIA devices. Therefore, devices that previously have not been able to be equipt with PCMCIA interfaces because of size, cost, or other restrictions, would be able to be used with PC-cards according to the present invention.

As previously described some PC-cards are provided with a second connector/adaptor for I/O. For example, as illustrated in Fig. 1A, a PC-card 100, may be a modem card and provided with pin adaptor/connector 120, in addition to the PCMCIA standard 68-pin connector/interface 110. In a modem PC-card the adaptor/connector 120 allows the PC-card to be connected to a phone line, for example, so that the modem can send and receive information via the phone line. The interface 110 allows the modem to read and write data between the host computer system. However, if the host computer system does not have a PCMCIA adaptor and interface, the PC-card would not be able to be used with the system.

Although a host computer system may not have a PCMCIA interface, most computers (e.g., Unix-servers, X-terminals, desktop PCs, laptops, calculators, etc.) do contain some sort of serial interface, for example an RS-232 type interface. According to another embodiment of the invention, as illustrated in Fig. 4A, a PC-card modem is provided with a second pin-interface/adaptor 450 in addition to the 68 pin connector/interface 320. For use of a typical modem, only 3 pins are needed for operation; a phone data line-in, a phone data line-out, and GND pin. In a first mode of operation a phone line/adaptor 400 is connected to the inteface/adaptor 450 and 3 pins are used to communicate information over a phone line. In this mode the 68-pin connector/ interface 320 is connected with a computer system interface 490 for communicating data between the computer system and the PC-card modem 105. The interface 490 can be a PCMCIA standard interface for communication with the PC-card 105. In a second mode of operation, as illustrated by the exemplary embodiment shown in Fig. 4B, a PCMCIA interface 490 may not be available. In this case a typical PC-card would not be able to be used. Therefore, according to this embodiment of the invention a cord/adaptor 410 is provided. The cord/adaptor 410 is provided with three separate lines, for example, 420, 430, and 440. One skilled in the art will recognize the configuration of these lines (in a single cord for example) may be implemented in numerous ways, and that the three separate lines 420, 430, and 440 are used for illustrative purposes only.

Line 440 of the cord/adaptor 410 is the same as the line 440 shown if Fig. 4A and provides a phone line including ground as is known to those skilled in the art and described above in connection with Fig. 4A. Line 430 can be used to provide power to the PC-card that normally would be provided by the host computer system through the PC-card interface 320 and is connected to another pin of the connector interface 450.

Finally, line 420 is provided for connection with a serial interface. According, to a preferred embodiment this can be and RS-232 type interface. One skilled in the art will recognize that alternative interfaces could also be used. The line 420 is connected to the remainder of the pins in interface connector 450. Theses pins are then used to provide a handshaking signals and data between the modem and the serial interface of the host computer. According to this aspect of the invention, the versatility of the PC-card is vastly increased since most computers are provided with serial interfaces. This also allows the PC-card 105 to be used virtually anywhere, even when the host computer system is not provided with a PCMCIA interface. The present invention has been described by way of example, and modifications and variations of the exemplary embodiments will suggest themselves to skilled artisans in this field without departing from the spirit of the invention. The preferred embodiments are merely illustrative and should not be considered restrictive in any way. The scope of the invention is to be measured by the appended claims, rather than the preceding description, and all variations and equivalents which fall within the range of the claims are intended to be embraced therein.

Claims

Claims:

1. A PC-card adapted to operate in a standard mode and a non- standard mode of operation comprising: a first interface adapted to receive a plurality of pins from a second interface connector; a circuit connected to said first interface for monitoring signals appearing on said plurality of pins; and a switch for switching said PC-card between said standard and non- standard mode of operation, wherein said circuit activates said switch in response to signals received on said first interface to switch said PC-card from the standard mode of operation to the non-standard mode of operation.

2. The PC-card according to claim 1, wherein said circuit is an ASIC.

3. The PC-card according to claim 1, wherein the standard mode of operation is PCMCIA compatible.

4. The PC-card according to claim 1, said PC-card is a PCMCIA compatible card and said second interface is a non-PCMCIA compatible interface.

5. The PC-card according to claim 4, said second interface is a serial interface.

6. The PC-card according to claim 3, wherein when said circuit detects an invalid combination of said plurality of signals received by said first interface and said circuit activates said switch to place the PC-card in the non- standard mode of operation.

7. The PC-card according to claim 4, wherein said plurality of signals includes a card enable signal, a write signal, and a read signal, and said invalid combination is the substantially simultaneous activation of said card enable, write, and read signals.

8. The PC-card according to claim 1, wherein said plurality of signals includes a card enable signal, a write signal, and a read signal and said circuit activates said switch place said PC-card in the non-standard mode of operation when said card enable signal, write signal, and read signal are substantially simultaneously activated.

9. A PC-card adapted to operate in a standard mode and a non- standard mode of operation comprising: an first interface adapted to receive a plurality of pins from a second interface connector, said second interface being one of a plurality of types of interfaces; means for setting said PC-card to operate in the standard mode and non- standard mode of operation based on the type said second interface connected to said first interface.

10. The PC-card according to claim 7, wherein the standard mode operation complies with the PCMCIA operation.

11. The PC-card according to claim 7, wherein said PC-card is a

PCMCIA card said second interface is a non-PCMCIA compatible interface.

12. The PC-card according to claim 9, wherein said second interface is a serial interface.

13. A method of configuring a PC-card to provide multiple functionalities, comprising the steps of: monitoring signal on an interface of the PC-card; placing the PC-card into a standard mode of operation if said monitored signals provide a valid combination of signals; placing the PC-card into a non-standard mode of operation if said monitored signals provide an invalid combination of signals.

14. The method according to claim 13, wherein said standard mode is PCMCIA compatible.

15. A PC-card modem comprising: a first PC-card interface for connection with a host computer interface and; a second PC-card interface adapted to receive a plurality of types of a cord/adaptor, wherein when said first interface is connected to a host system said second interface is adapted to receive a phone line and when said first interface is not connected, said second interface is adapted to receive a second type of cord/adapter, said second type of cord/adaptor providing a phone line, power line, and serial data line.