Split transaction protocol for a bus system
AssigneeIntel Corporation
InventorsJohn I. Garney, John S. Howard
Life of this patent
Estimating the term…
Abstract
A method of and apparatus for communicating between a host and an agent. The method includes the step of performing a first transaction between a host controller and a hub. The hub is operable to perform a single transaction with an agent based on the first transaction. The method then includes the step of performing a second transaction between the host controller and the hub. The second transaction is based on the single transaction.
Claims20
A controller hub comprising:
- an upstream port to receive a start split transaction to indicate a beginning of a transfer, the upstream port to operate at a high speed;
- a downstream port that is capable to operate at a low-speed, the downstream port to transmit an in token, to receive data, and to provide an acknowledgement in response to the receipt of the data, wherein the token includes a transfer type and a data rate identification;
- and
- a buffer to buffer the data from the downstream port and send the data to the upstream port after a speed conversion from the low-speed to the high-speed, the upstream port to transmit a complete split transaction in response to receiving the data.
A controller hub comprising:
- an upstream port to send a start split transaction to indicate a beginning of a transfer and data, the host interface to operate at a high speed;
- a downstream port that is capable to operate at a low-speed, the downstream port to receive an out token and the data, wherein the token includes a transfer type and a data rate identification;
- and
- a buffer to buffer the data from the upstream port and send the data to the downstream port after a speed conversion from the high-speed to the low-speed, the upstream port to transmit a complete split transaction and the out token in response to an acknowledgment at the downstream port.
A host controller, wherein the host controller is to issue a split transaction and complete split transaction, wherein the split transaction and complete split transaction include at least a token phase including a transfer type and a data rate identification, and the complete split transaction communicates buffered information to the host controller and the buffered information is received at the host controller at a different data rate than it is to be sent to a buffer.
A tangible, non-transitory, computer-readable medium comprising code to direct a processor to:
- receive a start split transaction and a token at an upstream port to indicate a beginning of a data transfer, wherein the upstream port is to operate at a high speed;
- send the token at low-speed to a downstream port, wherein the token includes a transfer type and a data rate identification;
- and
- transfer data to or from the downstream port, wherein the token or the data is buffered.
Dependencies are inferred from the claim text.