Command transfer controlling apparatus and command transfer controlling method
View Patent ↗Commands received from an apparatus that does not support virtual channels are assigned to a virtual channel. A command receiver 210 receives, from an external command transmitting entity that does not support virtual channels, a command designating an address. An assignment information storage unit 228 stores an assignment table in which an address space is divided into a plurality of areas and a channel is assigned to each area. A command storage unit 230 contains queues provided for respective channels, wherein each queue stores received commands temporarily. A distribution destination specifying unit 224 specifies a queue corresponding to an address by referring to the assignment table, and an execution unit 222 transfers the received command to the command storage unit 230 that corresponds to the specified queue.
1. A command transfer controlling apparatus, comprising:
a command receiver operable to receive a command having a specified address indicating a destination of writing a result of executing the command, from an external command transmitting entity which does not uniquely specify a command execution entity;
a channel assignment unit operable to assign, to the command, a channel for transfer assigned to the address specified by the received command and indicating the destination, by referring to an assignment table in which an address range is divided into a plurality of areas and a channel is assigned to each area;
a command storage unit operable to temporarily store the received commands in a queue, of a plurality of queues, corresponding to the channel assigned to the command; and
a command transfer unit operable to transfer, of the commands respectively stored in the plurality of queues, a command, to which a predetermined channel is assigned, to a command execution unit, in preference to commands assigned to other channels.
2. A command transfer controlling apparatus according to claim 1 , wherein said channel assignment unit is operable to specify a channel to be assigned, according to a predetermined part of the address specified by the received command and indicating the destination of writing the result of executing the command.
3. A command transfer controlling apparatus according to claim 1 , wherein said command transfer unit is operable to select a channel to which a command is to be issued in a manner that commands are issued at a predetermined rate among a plurality of such channels.
4. A command transfer controlling apparatus according to claim 1 , wherein the command execution entity is formed as a single-chip electronic device.
5. A command transfer controlling apparatus according to claim 1 , wherein said command transfer controlling apparatus and the command execution entity are formed integrally as a single-chip electronic device.
6. A command transfer controlling apparatus according to claim 1 , wherein said apparatus is formed as an electronic device physically separated from the command transmitting entity.
7. A command transfer controlling apparatus according to claim 1 , wherein the channel assignment unit is operable to dynamically change the address range which indicates the destination of writing the result of executing the command and which should be assigned to each of a plurality of channels, such that the rate of the number of commands stored in a given queue, of a plurality of queues, to that stored in another queue is lower than a predetermined rate.
8. A command transfer controlling method, comprising:
receiving, from an external command transmitting entity which does not uniquely specify a command execution entity, a command having a specified address indicating a destination of writing a result of executing the command;
assigning, to the command, a channel for transfer assigned to the address specified by the received command and indicating the destination, by referring to an assignment table in which an address range is divided into a plurality of areas and a channel is assigned to each area;
storing the received commands temporarily in a queue, of a plurality of queues, corresponding to the channel assigned to the command; and
transferring, of the commands respectively stored in the plurality of queues, a command, to which a predetermined channel is assigned, to a command execution unit, in preference to commands assigned to other channels.
9. A command transfer controlling method according to claim 8 , wherein the step of assigning dynamically changes the address range which indicates the destination of writing the result of executing the command and which should be assigned to each of a plurality of channels, such that the rate of the number of commands stored in a given queue, of a plurality of queues, to that stored in another queue is lower than a predetermined rate.
10. A storage medium containing a command transfer controlling program executable by a computer, the program causing the computer to perform functions, including the functions of:
receiving, from an external command transmitting entity which does not uniquely specify a command execution entity, a command having a specified address indicating a destination of writing a result of executing the command;
assigning, to the command, a channel for transfer assigned to the address specified by the received command and indicating the destination, by referring to an assignment table in which an address range is divided into a plurality of areas and a channel is assigned to each area;
storing the received commands temporarily in a queue, of a plurality of queues, corresponding to the channel assigned to the command; and
transferring, of the commands respectively stored in the plurality of queues, a command, to which a predetermined channel is assigned, to a command execution unit, in preference to commands assigned to other channels.
11. A storage medium according to claim 10 , wherein the function of assigning dynamically changes the address range which indicates the destination of writing the result of executing the command and which should be assigned to each of a plurality of channels, such that the rate of the number of commands stored in a given queue, of a plurality of queues, to that stored in another queue is lower than a predetermined rate.