US 5,680,555 AGranted

Host adapter providing automatic terminator configuration

AssigneeComputer Performance, Inc.

InventorsMartin J. Bodo, Robert A. Rosenbloom

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Abstract

A host adapter, having at least two connectors which both belong to a single digital computer bus, includes a first terminator that is coupled to a first portion of the digital computer bus, and a second terminator that is coupled to a second, separate portion of the bus. Upon being enabled by a control signal, these terminators respectively terminate the first and second portions of the bus. The host adapter also includes termination control logic coupled to the first and second terminators, and to connectors for the bus. The termination control logic receives connection signals from the connectors which indicate connection or non-connection of a device to the first portion, or to the combined first and second portions of the bus. The termination control logic processes these connection sensing signals and transmits two independent control signals which appropriately enable or disable the first and second terminators. The host adapter may also include a third connector that also belongs to the bus, and from which the termination control logic also receives connection sensing signals. In addition to providing control signals for the terminators, the termination control logic also detects and indicates if devices are improperly connected to the bus.

Claims27

Dependent claims

A host adapter adapted for inclusion into a digital computer system, the host adapter comprising:

at least two connectors, each such connector belonging to a digital computer bus;
a first terminator coupled to a first portion of the digital computer bus for electrically terminating the first portion of the digital computer bus, said first terminator being responsive to a first terminator control signal for enabling said first terminator and for disabling said first terminator;
a second terminator coupled to a second portion of the digital computer bus, that is separate from the first portion of the digital computer bus, for electrically terminating the second portion of the digital computer bus;
said second terminator being responsive to a second terminator control signal for enabling said second terminator and for disabling said second terminator;
termination control logic coupled to said first terminator, to said second terminator and to said connectors:
for receiving a first connection sensing signal from each such connector which indicates connection or non-connection of a device to the first portion of the digital computer bus;
for receiving a second connection sensing signal from each such connector which indicates connection or non-connection of a device to the second portion of the digital computer bus;
for processing the two first connection sensing signals received respectively from each of said connectors, and the two second connection sensing signals received respectively from each of said connectors;
and
for transmitting, in response to such connection sensing signals processing, both the first terminator control signal to said first terminator to enable or disable said first terminator, and the second terminator control signal to said second terminator to enable or disable said second terminator,
whereby the host adapter automatically configures both said first terminator and said second terminator for properly terminating the digital computer bus for operation with all devices coupled to said connectors.

8 more elements

A computer system comprising:

a device;
a digital computer bus to which said device connects;
and
a digital computer host system including a host adapter having at least two connectors that belong to the digital computer bus, the host adapter including:
at least two connectors, each such connector belonging to a digital computer bus;
a first terminator coupled to a first portion of the digital computer bus for electrically terminating the first portion of the digital computer bus, said first terminator being responsive to a first terminator control signal for enabling said first terminator and for disabling said first terminator;
a second terminator coupled to a second portion of the digital computer bus, that is separate from the first portion of the digital computer bus, for electrically terminating the second portion of the digital computer bus;
said second terminator being responsive to a second terminator control signal for enabling said second terminator and for disabling said second terminator;
termination control logic coupled to said first terminator, to said second terminator and to said connectors:
for receiving a first connection sensing signal from each such connector which indicates connection or non-connection of a device to the first portion of the digital computer bus;
for receiving a second connection sensing signal from each such connector which indicates connection or non-connection of a device to the second portion of the digital computer bus;
for processing the two first connection sensing signals received respectively from each of said connectors, and the two second connection sensing signals received respectively from each of said connectors;
and
for transmitting, in response to such connection sensing signals processing, both the first terminator control signal to said first terminator to enable or disable said first terminator, and the second terminator control signal to said second terminator to enable or disable said second terminator,
whereby the host adapter automatically configures both said first terminator and said second terminator for properly terminating the digital computer bus for operation with all devices coupled to said connectors.

12 more elements

An automatic partial termination system for a digital computer bus comprising:

at least two connectors, each such connector belonging to a digital computer bus;
a first terminator coupled to a first portion of the digital computer bus for electrically terminating the first portion of the digital computer bus, said first terminator being responsive to a first terminator control signal for enabling said first terminator and for disabling said first terminator;
a second terminator coupled to a second portion of the digital computer bus, that is separate from the first portion of the digital computer bus, for electrically terminating the second portion of the digital computer bus;
said second terminator being responsive to a second terminator control signal for enabling said second terminator and for disabling said second terminator;
termination control logic coupled to said first terminator, to said second terminator and to said connectors:
for receiving a first connection sensing signal from each such connector which indicates connection or non-connection of a device to the first portion of the digital computer bus;
for receiving a second connection sensing signal from each such connector which indicates connection or non-connection of a device to the second portion of the digital computer bus;
for processing the two first connection sensing signals received respectively from each of said connectors, and the two second connection sensing signals received respectively from each of said connectors;
and
for transmitting, in response to such connection sensing signals processing, both the first terminator control signal to said first terminator to enable or disable said first terminator, and the second terminator control signal to said second terminator to enable or disable said second terminator,
whereby the automatic partial termination system automatically configures both said first terminator and said second terminator for properly terminating the digital computer bus for operation with all devices coupled to said connectors.

8 more elements

Dependencies are inferred from the claim text.