Delaying arbitration of bus access in digital computers

Claim 1

A computer system with bus arbitration, comprising: (a) a plurality of devices sharing a common bus, any one of said devices asserting a request signal on said bus after said any one requires control of the bus and wherein all of said devices which may require control of said bus have means for detecting said request signal; (b) arbitration circuitry coupled to said bus and detecting said request signal and asserting an arbitrate signal on said bus in response to said request signal; (c) only those of said devices requiring control of said bus asserting a priority signal in response to said arbitrate signal, and one of the devices asserting a highest level of priority gaining control of said bus; (d) said one of the devices including a timing circuit to prevent said one of the devices from reasserting said request signal for at least a first preselected time period after relinquishing control of said bus and after said one of the devices requires control of said bus.

Claim 16

A method for arbitrating for control of a common bus shard by a plurality of devices in a computer system, comprising the step of: a) providing a condition wherein a device requests control of said bus, wherein all of said devices wanting control of said bus can provide said condition; b) detecting said condition wherein said device requests control of said bus, and a condition wherein any device previously having control of said bus has relinquished control; c) when said conditions have been detected, asserting an arbitrate condition by signaling to all of said devices via said bus; d) detecting said arbitrate condition at all of said devices requesting control of said bus and asserting a priority code onto said bus by only those of said devices requesting control of said bus; e) withdrawing said priority code by all of said devices asserting a lower priority code to leave only a highest of the priority codes asserted, and the one of said devices asserting said highest of the priority codes assuming control of said bus; f) when said one of said devices as completed use of said bus, said one of said devices relinquishing control of said bus and refraining from providing said condition wherein said device requests control of said bus for at least a first preselected period of time after said device wants control of said bus.

Claim 17

A method for arbitrating for control of a common bus shard by a plurality of devices in a computer system, comprising the step of: a) providing a condition wherein a device requests control of said bus, wherein all of said devices wanting control of said bus can provide said condition; b) detecting said condition wherein said device requests control of said bus, and a condition wherein any device previously having control of said bus has relinquished control; c) when said conditions have been detected, asserting an arbitrate condition by signaling to all of said devices via said bus; d) detecting said arbitrate condition at all of said devices requesting control of said bus and asserting a priority code onto said bus by only those of said devices requesting control of said bus; e) withdrawing said priority code by all of said devices asserting a lower priority code to leave only a highest of the priority codes asserted, and the one of said devices asserting said highest of the priority codes assuming control of said bus; f) when said one of said devices as completed use of said bus, said one of said devices relinquishing control of said bus and refraining from providing said condition wherein said device requests control of said bus for at least a first preselected period of time after said device wants control of said bus.

Claim 25

A method for arbitrating for control of a common bus shared by first and second CPU devices and a plurality of other devices in a computer system, comprising the steps of: a) detecting a condition wherein any one of said devices requests control of said bus; b) asserting an arbitrate condition in response to detecting said request condition by signaling to all of said devices via said bus; c) detecting said arbitrate condition at all of said devices requesting control of said bus and asserting a priority code onto said bus only those of said devices requesting control of said bus to determine which one of said devices is asserting a highest of the priority codes and allowing said one of the devices to assume control of said bus; d) when said one of the devices has completed use of said bus, said one of the devices relinquishing control of said bus and refraining from requesting control of said bus for at least a first preselected period of time after said one of the devices wants control of said bus.

Claim 26

A method for arbitrating for control of a common bus shared by first and second CPU devices and a plurality of other devices in a computer system, comprising the steps of: a) detecting a condition wherein any one of said devices requests control of said bus; b) asserting an arbitrate condition in response to detecting said request condition by signaling to all of said devices via said bus; c) detecting said arbitrate condition at all of said devices requesting control of said bus and asserting a priority code onto said bus only those of said devices requesting control of said bus to determine which one of said devices is asserting a highest of the priority codes and allowing said one of the devices to assume control of said bus; d) when said one of the devices has completed use of said bus, said one of the devices relinquishing control of said bus and refraining from requesting control of said bus for at least a first preselected period of time after said one of the devices wants control of said bus.