Apparatus and method for providing access security to a device coupled upon a two-wire bidirectional bus
First Claim
1. A computer system incorporating a plurality of securable devices coupled to a two-line bi-directional bus, said computer system comprising:
- a keyboard;
a storage unit operably coupled to the keyboard to produce an unlock signal upon an output conductor of the storage unit if a stored password within the storage unit favorably compares with a password entered upon the keyboard; and
a controller coupled to the storage unit for allowing access to a first address of the securable device upon receiving the unlock signal and wherein access to a second address of the securable device is allowed regardless of whether the stored password compares with the password entered upon the keyboard.
4 Assignments
0 Petitions
Accused Products
Abstract
A computer system, bus interface unit, and method are provided for securing certain devices connected to an I2C bus. Those devices include any device which contains sensitive information or passwords. For example, a device controlled by a I2C-connected device bay controller may contain sensitive files, data, and information to which improper access may be denied by securing the device bay controller. Moreover, improper accesses to passwords contained in non-volatile memory connected to the I2C bus must also be prevented. A bus interface unit coupled within the computer contains registers, and logic which compares the incoming I2C target and word addresses with coded bits within fields of those registers. If the target or word address is to a protected address or range of addresses, then an unlock signal must be issued before the security control logic will allow the target or word address to access the I2C bus or addressed device thereon. The unlock signal can be assigned to a particular slot among numerous slots, wherein the slots are arranged in hierarchical order. This allows a system administrator the capability to unlock accesses to protected non-volatile memory, and thereby allowing the system administrator to change passwords within one portion of non-volatile memory, and possibly allowing a lower priority user to access and change a password within another portion of non-volatile memory. The slot which accommodates an unlock signal assigned to the system administrator is altogether separate from a slot assigned to a non-system administrator or user.
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Citations
20 Claims
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1. A computer system incorporating a plurality of securable devices coupled to a two-line bi-directional bus, said computer system comprising:
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a keyboard;
a storage unit operably coupled to the keyboard to produce an unlock signal upon an output conductor of the storage unit if a stored password within the storage unit favorably compares with a password entered upon the keyboard; and
a controller coupled to the storage unit for allowing access to a first address of the securable device upon receiving the unlock signal and wherein access to a second address of the securable device is allowed regardless of whether the stored password compares with the password entered upon the keyboard. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
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9. A bus interface unit coupled to an inter integrated circuit (I2C) bus upon which a plurality of I2C devices are connected, the bus interface unit comprising:
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a storage unit configured to retain a stored password;
a security mapping register comprising a field of bits which identify a password secured device among the plurality of I2C devices;
a comparator coupled to the storage unit for comparing a user entered password against the stored password and to present an unlock signal from the comparator if the user entered password favorably compares with the stored password; and
security control logic operably coupled between the comparator and the security mapping register for allowing access to the password secured device upon receipt of the unlock signal. - View Dependent Claims (10, 11, 12, 13, 14, 15)
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16. A method for unlocking a plurality of password securable devices, comprising:
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comparing a user-entered password against a stored password;
comparing a target address issued to an inter integrated circuit (I2C) device against a field code within a security mapping register to determine if the target address is a password secured address; and
presenting an unlock signal to the I2C device to de-assert lock thereof if the user-entered password is the same as the stored password and, if the user-entered password is not the same as the stored password, asserting lock only to the I2C device having the target address while the remaining plurality of password securable devices are unlocked and operable. - View Dependent Claims (17, 18, 19, 20)
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Specification