Method and apparatus for reducing checking costs in fault tolerant processors
First Claim
1. An apparatus comprising:
- a central processing unit comprising;
first and second processors to process an identical instruction stream;
a data bus coupled to said first and second processors;
means for providing said first processor to furnish data to said data bus and to receive data from said data bus in response to said identical instruction stream; and
means for providing said second processor to receive data from said data bus in response to said identical instruction stream.
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Accused Products
Abstract
According to one aspect of the invention, an apparatus includes a first processor coupled to a first system bus to provide data to a cache and a memory, and a second processor coupled to the first system bus and a second abbreviated system bus to receive read data from said first system bus. In accordance with a further aspect of the invention, an apparatus includes means for correcting errors in memory. In accordance with a further aspect of the invention, an apparatus includes a number of computing systems each including a memory device mounted on an infrequently replaced hardware unit, and capable of communicating with the number of computing systems. In accordance with another aspect of the invention, an apparatus includes a counter, means for detecting a selected state of said counter, and means, responsive to output signals from said counter, for selectively permitting or inhibitting transfer of data fed to a recirculating state device. In accordance with a further aspect of the invention, an apparatus includes a first means for providing a first clocking signal, a second means for providing a second clocking signal, means for providing an error signal responsive to an offset between edges of the first and second clocking signals.
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Citations
11 Claims
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1. An apparatus comprising:
a central processing unit comprising; first and second processors to process an identical instruction stream; a data bus coupled to said first and second processors; means for providing said first processor to furnish data to said data bus and to receive data from said data bus in response to said identical instruction stream; and means for providing said second processor to receive data from said data bus in response to said identical instruction stream. - View Dependent Claims (2, 3, 4, 5, 6, 7)
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8. An apparatus comprising:
a central processing unit comprising; first and second processors to process an identical instruction stream; a first system bus comprising a data bus coupled to said first and second processors with said first processor providing data to said data bus and receiving data from said data bus in response to said identical instruction stream and said second processor receiving data from said data bus and checking said data on said data bus for accuracy, said first system bus further comprising; a first address bus, a first error bus and a first control bus coupled to said first processor; and
with said apparatus further comprisinga second abbreviated system bus coupled to said second processor comprising a second address bus, a second error bus and a second control bus, and said data bus of said first system bus. - View Dependent Claims (9, 10, 11)
Specification