Method and apparatus for performing bus transactions in a computer system

Claim 3

The method as defined in claim 1 wherein the second token is the same as the first token, such that the first agent identifies the second token as corresponding the address by comprising the first token and the second token to determine if the token and the second token are the same.

Claim 4

The method as defined in claim 1 wherein the step of driving the first token comprises driving the first token when requested data is not ready.

Claim 5

The method as defined in claim 1 wherein the step of driving the data occurs after requested data is ready.

Claim 6

The method defined in claim 1 wherein the step of sending the deferred reply comprises sending at least one completion signal to the first agent.

Claim 7

The method defined in claim 1 wherein the step of sending the deferred reply comprises driving data on the data bus.

Claim 10

The method as defined in claim 7 wherein the first token comprises the address.

Claim 11

The method defined in claim 7 wherein the step of sending the deferred reply comprises sending at least one completion signal to the first agent.

Claim 12

The method defined in claim 7 wherein the step of sending the deferred reply comprises driving data on the data bus.

Claim 13

A computer system comprising: a first bus means for communicating address information; a second bus means for communicating data information; at least one requesting agent coupled to the first bus and the second bus, wherein said at least one requesting agent is capable of initiating a bus operation; at least one responding agent coupled to the first bus means and the second bus means, wherein said at least one responding agent is capable of responding to a request from said at least one requesting agent, such that a response is sent on the second bus means in response to said request; wherein said at least one responding agent drives a first token on the second bus means as its response when said at least one responding agent is not ready to fulfill the bus request, and wherein said at least one requesting agent receives the first token from the second bus means, and wherein said at least one responding agent drives a second token on the first bus means and a deferred reply when ready to fulfill the bus request, wherein said at least one requesting agent receives the second token from the first bus means, and further wherein the second token is identified by said at least one requesting agent as corresponding to the bus request, such that said at least one requesting agent latches the deferred reply to complete the bus transaction.

Claim 14

A computer system comprising: a first bus means for communicating address information; a second bus means for communicating data information; at least one requesting agent coupled to the first bus and the second bus, wherein said at least one requesting agent is capable of initiating a bus operation; at least one responding agent coupled to the first bus means and the second bus means, wherein said at least one responding agent is capable of responding to a request from said at least one requesting agent, such that a response is sent on the second bus means in response to said request; wherein said at least one responding agent drives a first token on the second bus means as its response when said at least one responding agent is not ready to fulfill the bus request, and wherein said at least one requesting agent receives the first token from the second bus means, and wherein said at least one responding agent drives a second token on the first bus means and a deferred reply when ready to fulfill the bus request, wherein said at least one requesting agent receives the second token from the first bus means, and further wherein the second token is identified by said at least one requesting agent as corresponding to the bus request, such that said at least one requesting agent latches the deferred reply to complete the bus transaction.

Claim 15

The computer system as defined in claim 7 wherein the first bus means comprises an address bus and the second bus means comprises a data bus.

Claim 16

The computer system as defined in claim 7 wherein said at least one responding agent is not ready to respond to the bus request because data corresponding to the request is not available.

Claim 19

The method as defined in claim 14 wherein the step of sending a deferred response includes the step of driving a first token on the data bus in response to the address, wherein the step of driving a first token is performed by a second agent, such that the token becomes one of a series of responses on the data bus, and wherein the series of responses is ordered in the same order as the series of addresses; and wherein the step of receiving the deferred response includes the step of receiving the first token from the data bus, wherein the first token is received by the first agent.

Claim 20

The method as defined in claim 14 wherein the step of sending a deferred reply includes the step of driving a second token on the address bus, wherein the second token is driven by the second agent; and wherein the step of receiving the deferred reply includes the step of receiving the second token from the address bus, wherein the second token is received by the first agent, such that the first agent identifies the second token as corresponding to the address.

Claim 23

The method as defined in claim 17 wherein the second token is the same as the first token, such that the first agent identifies the second token as corresponding to the address by comparing the first token and the second token to determine if the first and the second token are the same.

Claim 24

The method as defined in claim 17 wherein the step of driving the first token on the data bus comprises driving the address on the data bus.

Claim 27

The method defined in claim 20 wherein the step of identifying includes comparing the first token and the second token and receiving the deferred reply if the first token and the second match.

Claim 28

The method defined in claim 20 further comprising the step of buffering the address and the first token for use as a reference when receiving the deferred reply.

Claim 31

The method defined in claim 23 wherein the first token comprises the address.

Claim 32

A computer system comprising: an address bus; a data bus; a control bus; a first bus agent coupled to the address bus, the data bus, and the control bus for performing a bus operation, wherein the first bus agent initiates the bus operation by initiating a first bus transaction by driving a request address of a request onto the address bus during a first clock cycle, and terminates the first bus transaction upon receiving an immediate response to satisfy the request or upon receiving a deferral response indication on the control bus indicating response to the request is to be deferred and request identification information on the data bus.

Claim 33

A computer system comprising: an address bus; a data bus; a control bus; a first bus agent coupled to the address bus, the data bus, and the control bus for performing a bus operation, wherein the first bus agent initiates the bus operation by initiating a first bus transaction by driving a request address of a request onto the address bus during a first clock cycle, and terminates the first bus transaction upon receiving an immediate response to satisfy the request or upon receiving a deferral response indication on the control bus indicating response to the request is to be deferred and request identification information on the data bus.

Claim 34

The computer system defined in claim 25 further comprising a second bus agent for providing the immediate response to the first bus agent.

Claim 35

The computer system defined in claim 26 wherein the second bus agent performs a second bus transaction, wherein the second bus agent initiates the second bus transaction by driving the request identification information onto the address bus and by driving a deferral reply.

Claim 36

The computer system deferred in claim 27 wherein the first bus agent received the request identification information deferred reply and associates the deferred reply with the request on the first bus transaction to complete the bus operation.

Claim 37

The computer system defined in claim 28 wherein the first bus agent associates the deferred reply with the request using the request identification information.

Claim 38

The computer system defined in claim 25 further comprising a second bus for providing the deferral response to the first but agent.

Claim 39

The computer system defined in claim 25 wherein the request identification information comprises a token.

Claim 42

A computer system comprising: a bus including; an address bus; a response bus; a data bus; a requesting agent coupled to the bus, wherein the requesting agent issues a bus request on the address bus, handles deferral responses in response to requests, and maintains the bus request as pending until receiving a deferred reply; and a responding agent coupled to the bus, wherein the responding agent issues a token on the data bus and generates a deferral response when unable to complete a transaction during a predetermined time of the transaction, and generates the deferred reply and sends the token on the address bus when the responding agent is subsequently able to complete the transaction.

Claim 43

A computer system comprising: a bus including; an address bus; a response bus; a data bus; a requesting agent coupled to the bus, wherein the requesting agent issues a bus request on the address bus, handles deferral responses in response to requests, and maintains the bus request as pending until receiving a deferred reply; and a responding agent coupled to the bus, wherein the responding agent issues a token on the data bus and generates a deferral response when unable to complete a transaction during a predetermined time of the transaction, and generates the deferred reply and sends the token on the address bus when the responding agent is subsequently able to complete the transaction.