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US 7,003,616 B2Granted
Communication control method, communication system, print control apparatus, printing apparatus, host apparatus, peripheral apparatus, and storage medium
AssigneeCanon Kabushiki Kaisha
InventorAkihiro Shimura
Life of this patent
Estimating the term…
Abstract
A communication system for issuing commands from an initiator to a target, thereby allowing the target to write or read out data into/from a memory area which the initiator has and exchanging the data. The initiator transmits read and write commands for the memory area to the target so as not to exceed the total number of commands which can be held by the target. The target holds the received read and write commands, holds references to the commands by different queues, and independently processes the commands, so that the number of the commands to be transmitted can be managed efficiently.
Claims31
A communication control method of exchanging data between an initiator and a target, comprising:
- a transmitting step of transmitting a read command and/or a write command from the initiator to the target so as not to exceed a total number of commands which can be held in the target, each command corresponding to a designation indicating to which one of a plurality of queues provided in the target the command corresponds;
- a holding step of holding, in the target, the transmitted read and/or write commands;
- a queuing step of queuing in the target, a reference to each of the read and/or write commands held in the target into a respective one of the plurality of queues designated by the designation corresponding to each command;
- and
- a performing step of performing, in the target, a read operation to read data from a designated location in a memory area of the initiator or a write operation to write data into a designated location in the memory area of the initiator in accordance with the held read or write command.
2 more elements
A communication system for exchanging data between an initiator and a target, comprising:
- the initiator adapted to:
- transmit a read command and/or a write command to the target so as not to exceed the total number of commands which can be held in the target, each command corresponding to a designation indicating to which one of a plurality of queues provided in the target the command corresponds;
- and
- the target adapted to:
- hold the transmitted read and/or write commands;
- queue a reference to each of the read and/or write commands held by said target into a respective one of the plurality of queues designated by the designation corresponding to each command;
- and
- perform a read operation to read data from a designated location in a memory area of the initiator or a write operation to write data into a designated location in the memory area of the initiator in accordance with the held read or write command.
5 more elements
A communication control method of exchanging data between an initiator and a target, comprising:
- a command forming step of forming, in the initiator, a command corresponding to a designation indicating to which one of a plurality of queues provided in the target the command corresponds;
- and
- a transmitting step of transmitting the formed command from the initiator to the target so as not to exceed a total number of commands which can be held in the target,
- wherein the target holds the transmitted command, queues a reference to the command held by the target into a respective one of the plurality of queues designated by the designation corresponding to the command, and performs a read operation to read data from a designated location in a memory area of the initiator or a write operation to write data into a designated location in the memory area of the initiator in accordance with the command referred to by the reference queued in the one queue.
1 more element
A communication control method of controlling a target that exchanges data with an initiator, comprising:
- a storing step of storing a command received from the initiator, the command corresponding to a designation indicating to which one of a plurality of queues provided in the target the command corresponds;
- a queuing step of registering reference data to refer to the command stored by said storing step into a respective one of the plurality of queues designated by the designation corresponding to the command;
- and
- an executing step of executing a read operation to read data from a designated location in a memory area of the initiator or a write operation to write data into a designated location in the memory area of the initiator in accordance with the command referred to by the reference data registered in the one queue.
1 more element
A communication control apparatus exchanging data with an external apparatus, said communication control apparatus comprising:
- a command forming unit, adapted for forming a command corresponding to a designation indicating to which one of a plurality of queues provided in the external apparatus the command corresponds;
- and
- a transmitting unit, adapted for transmitting the command formed by said command forming unit to the external apparatus so as not to exceed the total number of commands which can be held by the external apparatus,
- wherein the external apparatus holds the command transmitted by said transmitting unit, queues a reference to the command held by the external apparatus into a respective one of the plurality of queues designated by the designation corresponding to the command, and performs a read operation to read data from a designated location in a memory area of said communication control apparatus or a write operation to write data into a designated location in the memory area in accordance with the command referred to by the reference queued in the one queue.
1 more element
A communication control apparatus for exchanging data with an external apparatus, said communication control apparatus comprising:
- a storing unit, adapted for storing a command received from the external apparatus, the command corresponding to a designation indicating to which one of a plurality of queues provided in said communication control apparatus the command corresponds;
- a queuing unit, adapted for registering reference data to refer to the command stored by said storing unit into a respective one of the plurality of queues designated by the designation corresponding to the command;
- and
- an executing unit, adapted for executing a read operation to read data from a designated location in a memory area of the external apparatus or a write operation to write data into a designated location in the memory area in accordance with the command referred to by the reference data registered by said queuing unit in the one queue.
1 more element
A communication control method of exchanging data between a plurality of devices, comprising:
- a transmitting step of transmitting a command from a first device among the plurality of devices to a second device among the plurality of devices so as not to exceed a total number of commands which can be held in the second device, each command corresponding to a designation indicating to which one of a plurality of queues provided in the second device the command corresponds;
- a holding step of holding, in the second device, the transmitted command;
- a queuing step of queuing in the second device, a reference to the command held in the second device into a respective one of the plurality of queues designated by the designation corresponding to the command;
- and
- a performing step of performing, in the second device, a read operation to read data from a designated location in a memory area of the first device or a write operation to write data into a designated location in the memory area of the first device in accordance with the held command.
2 more elements
Dependencies are inferred from the claim text.