Removable Mother/Daughter Peripheral Card

Abstract

A peripheral card having a Personal Computer (“PC”) card form factor and removably coupled externally to a host system is further partitioned into a mother card portion and a daughter card portion. The daughter card is removably coupled to the mother card. In the preferred embodiment, a low cost flash “floppy” is accomplished with the daughter card containing only flash EEPROM chips and being controlled by a memory controller residing on the mother card. Other aspects of the invention includes a comprehensive controller on the mother card able to control a predefined set of peripherals on daughter cards connectable to the mother card; relocation of some host resident hardware to the mother card to allow for a minimal host system; a mother card that can accommodate multiple daughter cards; daughter cards that also operates directly with hosts having embedded controllers; daughter cards carrying encoded data and information for decoding it; and daughter cards with security features.

Description

CROSS REFERENCE TO RELATED APPLICATIONS[0001]This application is a continuation of application Ser. No. 11 / 463,158, filed Aug. 8, 2006, which is a divisional of application Ser. No. 10 / 050,429, filed May 15, 2002, which in turn is a continuation of application Ser. No. 09 / 887,197, filed Jun. 21, 2001, now U.S. Pat. No. 6,381,662, which in turn is a continuation of application Ser. No. 09 / 241,222, filed Feb. 1, 1999, now U.S. Pat. No. 6,266,724, which in turn is a continuation of application Ser. No. 08 / 781,539, filed Jan. 9, 1997, now U.S. Pat. No. 5,887,145, which in turn is a continuation of application Ser. No. 08 / 462,642, filed Jun. 5, 1995, now abandoned, which in turn is a continuation of application Ser. No. 08 / 398,856, filed Mar. 6, 1995, now abandoned, which in turn is a continuation of application Ser. No. 08 / 151,292, filed Nov. 12, 1993, now abandoned, which in turn is a continuation-in-part of application Ser. No. 08 / 115,428, filed Sep. 1, 1993, now abandoned, which appl...

AI Technical Summary

Benefits of technology

[0025]Partitioning the externally removable PC card into a mother card and daughter card portion allows the functional components of a peripheral implemented on a PC card to be advantageously partitioned.

[0027]In this way, a more cost-effective memory system is possible, especially in applications where magnetic floppy disks are to be replaced. This is because each daughter card containing only flash EEPROM acts essentially like a semiconductor flash EEPROM “floppy disk”, and need not have a controller on it. The one controller on the mother card can then serve any number of these flash EEPROM “floppy disks”. The cost of each flash EEPROM “floppy disk” is therefore significantly reduced by elimination of the controller on the “floppy disk” itself. The other advantage is an increase in system flexibility. The user can add or decrease memory capacity by choosing among daughter cards with various amount of installed memory chips. Also, with each update or upgrade of the controller, only the mother card need be replaced, the daughter card “floppy disk” being fully usable with the new mother card.

[0028]According to another aspect of the invention, a PC card is implemented with a comprehensive mother card portion containing the common functional components of a number of peripherals. Each peripheral then has the rest of the functional components residing on a daughter card. For example, a magnetic hard disk, a modem, and a network adapter all have common functional components similar to that of a flash EEPROM system, such as a host interface, a processor, and a ROM. By moving these common functional components to a comprehensive mother card, each individual peripheral will have less components on the daughter card, thereby reducing cost.

[0032]In this manner, a comprehensive, removable daughter card functions with a host system either directly when the host system is customized with the support components or indirectly via a mother card having the support components thereon, the mother card being connectable to the host system via a standard interface. This provides flexibility and system compatibility on the one hand and economy and convenience on the other.

[0034]According to another aspect of the invention, the removable daughter card has identifying data that is readable by the mother card or the host system coupled thereto. The identifying data includes information that identifies what type of peripheral device is implemented on the daughter card. In another embodiment, the identifying data includes an identity code assignable to the daughter card for operational expediency and security applications. The device type identification allows the support components such as a comprehensive controller as well as the host system to configure and adapt accordingly. It further provides a form of acknowledge signal in a connection protocol for the native interface of the daughter card. The unique identity code provides a basis for matching each removable daughter card to a specific host system or mother card, for managerial or security reasons.

Problems solved by technology

However, RAM is volatile memory; that is, when power to the computer system is disconnected, data stored in RAM is lost.

However, they are relatively slow, bulky and require high precision moving mechanical parts.

Consequently, they are not rugged and are prone to reliability problems, as well as being slower and consuming significant amounts of power.

Disk drives are obstacles in the quest towards greater portability and lower power consumption of computer systems.

However, ROM and PROM cannot be reprogrammed.

The requirement for additional support hardware (e.g. controller) and software (e.g. microcode or firmware and drivers) in these devices poses issues of cost and inflexibility in memory configuration as well as system updating and upgrading.

For example, when Flash EEPROM PC cards are used to replace magnetic floppies or other removable storage, the additional support hardware to implement the control functions may contribute significantly to the cost and other overhead of the product relative to the memory capacity they provide.

Their support hardware and software tend to add cost, overhead and inflexibility to the final products.

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