Processor I/O and interrupt filters allowing a co-processor to run software unknown to the main processor
First Claim
1. In a data processing system including a main processor and at least one input/output device connected to a bus, the improvement for configuring said system to allow the addition of a co-processor to operate concurrently with said main processor and selectively sharing utilization of said input/output device, comprising:
- means dynamically controlled by said main processor for selectively preventing direct access to said input/output device in response to an attempted access by said co-processor;
means connected to said means for selectively preventing for utilizing said main processor to service said attempted access of said input/output device by said co-processor when said means for selectively preventing has been enabled to prevent direct access to said input/output device by said co-processor; and
said means for selectively preventing and said main processor allowing concurrent utilization of said input/output device by said main processor and co-processor when said means for selectively preventing has not been enabled.
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Accused Products
Abstract
A co-processor is connectable to a main system data bus to run software unknown to the main processor. The main processor can concurrently run other software and maintains priority over shared I/O facilities by providing trapping logic incorporated in a random access memory and dynamically loadable by the master processor which contains data related to the current useability by the co-processor of a shared I/O device. Additional logic is associated with the co-processor to manage interrupts between the co-processor and the system bus.
77 Citations
20 Claims
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1. In a data processing system including a main processor and at least one input/output device connected to a bus, the improvement for configuring said system to allow the addition of a co-processor to operate concurrently with said main processor and selectively sharing utilization of said input/output device, comprising:
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means dynamically controlled by said main processor for selectively preventing direct access to said input/output device in response to an attempted access by said co-processor; means connected to said means for selectively preventing for utilizing said main processor to service said attempted access of said input/output device by said co-processor when said means for selectively preventing has been enabled to prevent direct access to said input/output device by said co-processor; and said means for selectively preventing and said main processor allowing concurrent utilization of said input/output device by said main processor and co-processor when said means for selectively preventing has not been enabled. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12)
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13. In a data processing system including a main processor and at least one input/output device connected to a bus, the method for configuring said system to allow the addition of a co-processor capable of operation concurrent with that of said main processor and selectively sharing utilization of said input/output device, comprising:
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selectively preventing direct access to said input/output device by said co-processor; utilizing said main processor to service an attempted access of said input/output device by said co-processor when said direct access to said input/output device by said co-processor has been selectively prevented; and allowing concurrent utilization of said input/output device by said main processor and co-processor when said direct access to said input/output device is not being selectively prevented. - View Dependent Claims (14, 15, 16, 17, 18, 19, 20)
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Specification