Semiconductor memory configured to emulate floppy and hard disk magnetic storage based upon a determined storage capacity of the semiconductor memory

• US 5,226,168 A
• Filed: 04/24/1990
• Issued: 07/06/1993
• Est. Priority Date: 04/25/1989
• Status: Expired due to Term

• Current Assignee: Seiko Epson Corporation (Seiko Group)
• Original Assignee: Seiko Epson Corporation (Seiko Group)
• Inventors: Kobayashi, Junichi, Ikeda, Masayuki, Tateno, Hiroaki, Samejima, Shogo
• Primary Examiner(s): Lee, Thomas C.
• Assistant Examiner(s): Harrity, Paul
• Application Number:
  US07/513,600
• Time in Patent Office: 1,169 Days
• Field of Search: 395/800, 395/500
• US Class Current: 703/25
• CPC Class Codes: G06F 12/0638 Combination of memories, e.g. ROM and RAM such as to permit replacement or supplementing of words in one module by words in another module address formation of the next microinstruction G06F9/26; masking faults in memories by using spares or by reconfiguring G11C29/70
• CPC Class Codes: G06F 2003/0697 device management, e.g. handlers, drivers, I/O schedulers
• CPC Class Codes: G06F 3/0601 Interfaces specially adapted for storage systems
• CPC Class Codes: G06F 3/0614 Improving the reliability of storage systems
• CPC Class Codes: G06F 3/0637 Permissions
• CPC Class Codes: G06F 3/0661 Format or protocol conversion arrangements
• CPC Class Codes: G06F 3/0664 at device level, e.g. emulation of a storage device or system
• CPC Class Codes: G06F 3/0679 Non-volatile semiconductor memory device, e.g. flash memory, one time programmable memory [OTP]
• CPC Class Codes: Y02D 10/00 Energy efficient computing, e.g. low power processors, power management or thermal management

Abstract

A compact, low power consumption, light weight, highly reliable and high speed information processing system is provided by employing a semiconductor auxiliary storage device in lieu of conventional magnetic storage or memory elements, such as floppy or hard disks. An access request to such a magnetic storage or memory element is converted to an access request for the semiconductor auxiliary storage which uses semiconductor integrated circuits without requiring any modification of existing programs, such as, application software and disk operating systems. A memory circuit in the semiconductor auxiliary storage comprises ROM and RAM, and a portion of the ROM contents is copied into the RAM so that access modification for programs and data is permitted while the basic program and data is retained in a nonvolatile manner.

Claims

1. An information processing system having a CPU and a main program and data storage unit, comprising:

auxiliary storage interface means for transferring data between said CPU and auxiliary storage devices, being configured to access at least one auxiliary magnetic storage device;

semiconductor storage means connected to said auxiliary storage interface means, for receiving, storing, and retrieving data and programs;

BIOS storage means coupled to said CPU and said semiconductor storage means for storing at least a portion of a BIOS that controls said semiconductor storage means so as to respond to said auxiliary storage interface means in the same manner as said auxiliary magnetic storage device;

determination means, coupled to said semiconductor storage means, for determining a storage capacity of said semiconductor storage means and for outputting one of a first and second signal indicative of said determination;

detection means, coupled to said determination means, for detecting when said semiconductor storage means is to be treated as one of a floppy disk type and hard disk type magnetic storage, said detection means, upon receiving said first signal from said determination means, detecting that said semiconductor storage means is to be treated as said floppy disk-type magnetic storage, and said detection means, upon receiving said second signal from said determination means, detecting that said semiconductor storage means is to be treated as said hard disk type magnetic storage; and

ID information storage means, connected to said semiconductor storage means and said detection means, for storing ID information used by said BIOS storage means to initialize and configure said semiconductor storage means in one of a plurality of predetermined storage formats corresponding to the type detected by said detection means.

2. The information processing system according to claim 1 wherein said semiconductor storage means stores a program including an access request to said auxiliary magnetic storage device memory means.

3. The information processing system according to claim 2 wherein said semiconductor storage means has a read-only memory and an erase/write memory, said information processing system including means for copying a portion of contents of said read-only memory to said erase/write memory.

4. The information processing system according to claim 3 further comprising means for translating between physical addresses of source and target memory locations when access is made to said semiconductor storage means.

5. The information processing system according to claim 2 wherein access to said semiconductor storage means is accomplished using translation means for translating an address for said auxiliary magnetic storage device to an address for said semiconductor storage means.

6. The information processing system according to claim 5 wherein said semiconductor storage means stores track ID information designated for said auxiliary magnetic storage device, said translation means employing said track ID information to make said address translation.

7. The information processing system according to claim 1 wherein access to said semiconductor storage means is accomplished using translation means for translating an address for said auxiliary magnetic storage device to an address for said semiconductor storage means.

8. The information processing system according to claim 7 wherein said semiconductor storage means has a read-only memory and an erase/write memory, said information processing system including means for copying a portion of contents of said read-only memory to said erase/write memory.

9. The information processing system according to claim 8 further comprising means for translating between physical addresses of source and target memory locations when access is made to said semiconductor storage means.

10. The information processing system according to claim 7 wherein said semiconductor storage means stores track ID information designated for said auxiliary magnetic storage device, said translation mens employing said track ID information to make said address translation.

11. The information processing system according to claim 10 wherein said semiconductor storage means has a read-only memory and an erase/write memory, said information processing system including means for copying a portion of the contents of said read-only memory to said erase/write memory.

12. The information processing system according to claim 1 wherein said semiconductor storage means has a read-only memory and an erase/write memory, said information processing system including means for copying a portion of the contents of said read-only memory to said erase/write memory.

13. The information processing system according to claim 12 further comprising means for translating between physical addresses of source and target memory locations when access is made to said semiconductor storage means.

14. The information processing system of claim 1 further comprising:

address translation means for translating auxiliary magnetic storage addresses to corresponding semiconductor storage addresses for accessing said semiconductor storage means.

15. The information processing system of claim 14 wherein:

said auxiliary magnetic storage addresses correspond to values for a total number of cylinders, heads, and sectors, a desired sector being addressed, and a sector length; and

said address translation means translates to addresses in said semiconductor storage means corresponding to the value of a product of the number of magnetic storage sectors and twice the cylinder number added to the number of heads and then added to one less than the sector number being addressed all multiplied by 128 and by a factor of 2 raised to the power of the desired sector length, and further summed with a predetermined minimum offset value determined by a memory size for storing track ID information.

16. The information processing system of claim 15 wherein the value of the sector size is first doubled prior to said translation.

17. The information processing system of claim 1 further comprising:

memory translation means for translating between read-only and erase/write memory physical addresses when access is made to said semiconductor storage means.

18. Semiconductor storage for use in an information processing system having a CPU, a main storage for programs and data, and configured to access auxiliary storage devices, comprising:

auxiliary storage interface means for transferring data between said CPU and auxiliary storage devices, being configured to access at least one auxiliary magnetic storage device;

semiconductor storage means connected to said auxiliary storage interface means, for receiving, storing, and retrieving data and programs;

BIOS storage means coupled to said CPU and said semiconductor storage means for storing at least a portion of a BIOS that controls said semiconductor storage means so as to respond to said auxiliary storage interface means in the same manner as said auxiliary magnetic storage device;

determination means, coupled to said semiconductor storage means, for determining a storage capacity of said semiconductor storage means and for outputting one of a first and second signal indicative of said determination;

detection means, coupled to said determination means, for detecting when said semiconductor storage means is to be treated as one of a floppy disk type and hard disk type magnetic storage, said detection means, upon receiving said first signal from said determination means, detecting that said semiconductor storage means is to be treated as said floppy disk-type magnetic storage, and said detection means, upon receiving said second signal from said determination means, detecting that said semiconductor storage means is to be treated as said hard disk type magnetic storage; and

ID information storage means, connected to said semiconductor storage means and said detection means, for storing ID information used by said BIOS storage means to initialize and configure said semiconductor storage means in one of a plurality of predetermined storage formats corresponding to the type detected by said detection means.

19. A method for providing semiconductor type auxiliary storage for an information processing system having a CPU and a main program and data storage unit, the method comprising the steps of:

providing an auxiliary storage interface for transferring data between said CPU and auxiliary storage devices, said auxiliary storage interface being configured to access at least one auxiliary magnetic storage device;

connecting at least one semiconductor memory device to said auxiliary storage interface for receiving, storing, and retrieving data and programs;

providing a least a portion of a Basic Input/Output Operating system (BIOS) in communication with both said CPU and said auxiliary storage interface for controlling said semiconductor memory device so as to respond to said auxiliary storage interface in the same manner as said auxiliary magnetic storage device;

determining a storage capacity of said semiconductor memory device and outputting a first and second signal indicative of said determination;

detecting when said semiconductor memory device is to be treated as one of a floppy disk type and hard disk type magnetic storage, wherein upon receiving said first signal being outputted in said determining and outputting step, detecting that said semiconductor memory device is to be treated as said floppy disk type magnetic storage, and wherein upon receiving said second signal being outputted in said determining and outputting step, detecting that said semiconductor memory device is to be treated as said hard disk type magnetic storage;

storing ID information comprising predetermined operating parameters for a plurality of magnetic storage formats corresponding to the type detected in said detecting step; and

initializing said semiconductor memory device using said BIOS so as to configure said semiconductor memory device in one of said plurality of storage formats based upon the type detected in said detecting step.

20. The method of claim 19 further comprising the steps of:

translating addresses requested for said auxiliary magnetic storage device to semiconductor memory addresses when data transfers are effected through said auxiliary storage interface; and

executing the translated request.

21. The method of claim 20 wherein said addresses are translated by adding an offset value, so as to reserve upper memory addresses for storage of said ID information, to a product of the sector size in bytes for the magnetic storage device being accessed and a quantity equal to the number of tracks prior to a current track being accessed for said magnetic storage device times the number of sectors per track which is then summed with one less than the sector number being addressed on the current track.

22. The method of claim 21 wherein the value of the sector size is adjusted to correspond to a desired size for storage media in said auxiliary magnetic storage device prior to said translation.

23. A method of utilizing semiconductor type auxiliary storage in an information processing system while permitting the utilization of existing software configured for use with conventional magnetic storage memory, comprising the steps of:

providing a semiconductor storage device for receiving, storing, and retrieving data and programs and having ID information stored therein corresponding to memory format structures for said conventional magnetic storage memory;

determining a relative storage capacity for said semiconductor storage device and providing a first and second signal indicative of said determination;

selecting a predetermined one of said memory format structures based on said ID information for said semiconductor storage device in response to the determined capacity by treating said semiconductor storage device as a floppy disk type magnetic storage when said first signal is provided in said determining and providing step, and treating said semiconductor storage device as a hard disk type magnetic storage when said second signal is provided in said determining and providing step;

initializing said semiconductor storage device to configure said semiconductor storage device in one of said memory format structures based upon the memory format structure selected in the selecting step;

capturing access requests for said conventional magnetic storage memory;

translating addresses in the access requests to addresses for said semiconductor storage device by employing said ID information; and

executing the translated access requests.

24. The method of claim 23 wherein said address is translated by adding a predetermined offset value, which reserves upper memory storage for said ID information, to a product of the sector size in bytes for the type of magnetic storage being accessed and a quantity equal to the number of tracks prior to a current track being accessed for said magnetic storage times the number of magnetic storage sectors per track and then added to one less than the sector number being addressed on the current track.

25. The method of claim 24 wherein the value of the sector size is adjusted to correspond to a desired size for storage media in said auxiliary magnetic storage device prior to said translation.