Protective bus interface and method
First Claim
1. A bus isolator for coupling a bus of a first predetermined configuration and signaling protocol (collectively the “
- first properties”
) to a peripheral via an I/O of a second predetermined configuration and signaling protocol (collectively the “
second properties”
), comprising;
a target interface coupled to the bus according to the first properties and configured to be responsive to a bus controller for transmission of data on the bus;
a master interface coupled to the I/O according to the second properties;
a controller coupled to and receiving signals from the target and master interfaces;
a memory coupled to the controller for storing signals received from the bus and the I/O; and
a processing element coupled to the controller and the memory and configured to manage the activity of the isolator and to verify the integrity of data contained in the signals received from the master interface, wherein data is transmitted from the target interface to the bus only in response to a data request from the bus controller.
2 Assignments
0 Petitions
Accused Products
Abstract
Method and apparatus are provided for preventing faulty commercial-off-the-shelf (COTS) peripherals or I/Os from disabling the bus to which they are connected. The apparatus has isolators coupled to the bus and the I/Os. A controller is coupled between the interfaces, a processor and memory, operating such that an I/O cannot transfer data to the bus without permission from the bus. Isolation memory keeps I/O and bus messages separate. I/O messages are checked before being sent to the bus. The method comprises: determining if there is a message for the peripheral, temporarily storing the message, determining if the message is for output or input, and if for output, sending it to the peripheral, and if for input, requesting and receiving it from the peripheral, temporarily storing and checking it, and transferring it to the bus only if valid. This prevents a failed I/O or peripheral from disabling the bus.
93 Citations
18 Claims
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1. A bus isolator for coupling a bus of a first predetermined configuration and signaling protocol (collectively the “
- first properties”
) to a peripheral via an I/O of a second predetermined configuration and signaling protocol (collectively the “
second properties”
), comprising;a target interface coupled to the bus according to the first properties and configured to be responsive to a bus controller for transmission of data on the bus; a master interface coupled to the I/O according to the second properties; a controller coupled to and receiving signals from the target and master interfaces; a memory coupled to the controller for storing signals received from the bus and the I/O; and a processing element coupled to the controller and the memory and configured to manage the activity of the isolator and to verify the integrity of data contained in the signals received from the master interface, wherein data is transmitted from the target interface to the bus only in response to a data request from the bus controller. - View Dependent Claims (2, 3, 4, 5, 6, 7)
- first properties”
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8. An electronic system operating in response to a bus controller, the electronic system comprising:
-
multiple peripherals; multiple COTS I/O elements, each coupled to one of the peripherals for passing signals to and from the one of the peripherals; multiple isolation elements, each coupled to at least one of the COTS I/O elements for passing signals to and from the at least one COTS I/O element; a bus coupled to the multiple isolation elements for sending and receiving signals to and from the peripherals via the isolation elements and the COTS I/O elements; and wherein each isolation element comprises; a target interface coupled to the bus for receiving commands from the bus controller and passing valid data requested by the bus controller from the peripheral to the bus; a master interface coupled to the at least one COTS I/O element for passing commands received from the bus to the peripheral and data requested from the peripheral back to the bus; a controller coupled to the target interface and the master interface for controlling command and data flow there between; a memory coupled to the controller for receiving commands and data from the bus and data from the at least one COTS I/O element; and a processing element coupled to the memory and the controller and configured to manage command and data flow between the bus and the at least one COTS I/O element such that the integrity of data contained in the signals received from the master interface is verified, and such that a signal from the at least one COTS I/O element is only transmitted to the bus in response to command received from the bus controller allowing such transfer. - View Dependent Claims (9, 10, 11)
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12. A method for coupling a bus and a peripheral via an isolator, comprising:
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determining whether there is a message for the peripheral; temporarily storing the message in the isolator; determining whether the message is for output to the peripheral or input from the peripheral; and if for output to the peripheral, sending the output to the peripheral; and if for input from the peripheral; receiving the input from the peripheral and temporarily storing it in the isolator; checking the input from the peripheral; and if valid, transferring the input from the peripheral to the bus in response to a request from a remote bus controller operating on the bus; and if not valid, not transferring the input from the peripheral to the bus. - View Dependent Claims (13, 14, 15, 16, 17, 18)
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Specification