Method for reprogramming flash ROM in a personal computer implementing an EISA bus system
First Claim
1. A method of reprogramming a portion of a sector in a flash ROM device, which is included in a PC system that includes RAM, wherein the sector includes at least two different programs, one of which is to be reprogrammed and one of which is not to be disturbed, the method comprising the steps of:
- (a) determining whether the flash ROM device is reprogrammed using five volts or twelve volts;
(b) responsive to a determination that the flash ROM device is reprogrammed using five volts;
(b)(1) detecting a write function request to the sector of flash ROM;
(b)(2) monitoring the address of the write request to prevent a write to the portion of the sector that is not to be disturbed;
(b)(3) placing the flash ROM in a Command Mode; and
(b)(4) writing the data to the portion of flash ROM which is to be reprogrammed.
6 Assignments
0 Petitions
Accused Products
Abstract
There is disclosed a method for reprogramming a 5 volt flash ROM, which includes EISA configuration code and boot code stored together in the same sector. The method of the present invention includes determining the type of flash ROM being used, and performing steps necessary to preserve the boot code while permitting reprogramming of the EISA configuration code. The method of the present invention includes modifying the conventional interrupt routine (Interrupt 15) that is used to set up and configure newly added expansion boards in an EISA bus system. The modified routine monitors the interrupt functions to determine if an erase or write is requested to the EISA configuration block in flash ROM. If an erase or write is detected, specific routines are initiated to enable the CPU to enter a protected mode to perform the necessary command sequences to the 5 volt flash ROM. In addition, necessary steps are taken to prevent the erasure of the boot code or other information in the sector that is not related to EISA configuration code during erase operations, and to prevent overwriting the boot code during write operations.
29 Citations
18 Claims
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1. A method of reprogramming a portion of a sector in a flash ROM device, which is included in a PC system that includes RAM, wherein the sector includes at least two different programs, one of which is to be reprogrammed and one of which is not to be disturbed, the method comprising the steps of:
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(a) determining whether the flash ROM device is reprogrammed using five volts or twelve volts; (b) responsive to a determination that the flash ROM device is reprogrammed using five volts; (b)(1) detecting a write function request to the sector of flash ROM; (b)(2) monitoring the address of the write request to prevent a write to the portion of the sector that is not to be disturbed; (b)(3) placing the flash ROM in a Command Mode; and (b)(4) writing the data to the portion of flash ROM which is to be reprogrammed. - View Dependent Claims (2, 3, 4, 5, 6, 7)
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8. A method of reprogramming a flash ROM that includes a multi-sector memory array having boot code and EISA configuration code stored in the same sector of the ROM'"'"'s'"'"'s memory array the method comprising the steps of:
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(a) determining whether flash ROM is reprogrammed using five volts; (b) if said flash ROM is reprogrammed using five volts; (b)(1) installing a new Interrupt 15 routine in place of an old Interrupt 15 routine; (b)(2) executing the new Interrupt 15 routine whenever an Interrupt 15 is requested; (b)(3) monitoring the Interrupt 15 request for an erase or write function; and (b)(4) executing an erase or write routine in response to the presence of an erase or write function. - View Dependent Claims (9, 10, 11, 12, 13, 14, 15)
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16. A method of reprogramming EISA configuration code in an AMD flash ROM device, wherein the flash ROM is divided into eight memory array sectors, and said EISA configuration code is stored in a single sector of the flash ROM together with boot code and Ediags instruction code, said method comprising the steps of:
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(a) initializing an Interrupt 15 routine; (b) determining if the flash ROM is reprogrammable using five volts; (c) modifying the Interrupt 15 routine in response to an affirmative determination in step b; (d) monitoring Interrupt 15 requests for the presence of an erase or a write function to EISA configuration code; (e) entering a 32 bit protective mode in response to the presence of an erase or write function in the Interrupt 15 request; (f) placing the flash ROM in a Command Mode by transmitting a sequence of command signals to various addresses in the flash ROM device; (g) erasing or writing to the EISA configuration code in the designated sector. - View Dependent Claims (17, 18)
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Specification