Electrical computers and digital processing systems: support – Clock – pulse – or timing signal generation or analysis
Reexamination Certificate
1999-03-15
2002-08-13
Gaffin, Jeffrey (Department: 2182)
Electrical computers and digital processing systems: support
Clock, pulse, or timing signal generation or analysis
C713S400000, C713S600000, C709S241000, C710S061000
Reexamination Certificate
active
06434705
ABSTRACT:
BACKGROUND OF THE INVENTION
This invention relates to an information processing apparatus, an information processing system, an information processing method and a providing medium, and more particularly to an information processing apparatus, an information processing system, an information processing method and a providing medium which allow, in order to perform an isochronous transaction between different environments in which different isochronization timings are used, establishment of isochronism between the different environments by comparing time information regarding to isochronization timings and by performing time management in different environments.
Standardization activity of a bridge format in the IEEE1394 environment is being proceeded by the P1394.1 (bridge) working group (refer to the P1394.1 Draft 0.03, Oct. 18, 1997). The IEEE1394 bridge (hereinafter referred to simply as bridge) is composed of a set of apparatus called portals connected to the IEEE1394 bus (hereinafter referred to suitably as bus), so that data can be transmitted between a plurality of (two or more) buses through the bridge. Transmission of data through the bridge (between portals) can be performed using, for example, a cable, a radio wave or an infrared ray.
The bridge can be used also for transaction between a wire environment and a radio environment. For example, as shown in
FIG. 6
, the bridge can be used for transaction therethrough between an IEEE1394 environment (wire environment) wherein nodes
101
-
1
to
101
-
6
are interconnected by an IEEE1394 bus (or an IEEE1394 cable) and a radio environment wherein a radio system is used for exchanging data between nodes
102
-
1
and
102
-
2
. In such a system as shown in
FIG. 6
, each node in the radio environment can be regarded as a member of the bridge. For example, in the system shown in
FIG. 6
, a combination of the node
102
-
1
and the node
101
-
16
can be treated as one bridge
110
.
By the way, the IEEE1394 standards prescribe that one cycle of isochronous transaction is 125 &mgr;s which is an interval of a cycle master node which is one of nodes connected to an IEEE1394 bus to transmit a cycle start packet. Each of the nodes receives the cycle start packet and adjusts (reset) the value (count value) of an own built-in cycle time register to establish cycle Isochronism (hereinafter referred to merely as isochronism).
However, in transaction between different environments through a bridge described above, since the reset interval (isochronization timing) of a cycle time register of each node differs from each environment (for example, the interval is 4 ms with the radio environment), matching of isochronization cannot be achieved.
SUMMARY OF THE INVENTION
It is thus an object of the present invention to provide an information processing apparatus, an information processing system, an information processing method and a providing medium which allow establishment of isochronism in isochronous transaction among different environments.
In order to attain the object described above, according to the present invention, when isochronous transaction is to be performed between different environments whose isochronization timings are different from each other, time information regarding isochronization timings of the individual environments is compared with each other, and time management between the environments is performed in response to a result of the comparison to establish isochronism between the different environments.
In particular, according to an aspect of the present invention, there is provided an information processing apparatus, including a comparison means for comparing first time information regarding an isochronization timing of isochronous transaction in a first environment and second time information regarding an isochronization timing of isochronous transaction in a second environment with each other, and a transmission means for transmitting a result of the comparison by the comparison means to another information processing apparatus of the second environment.
According to another aspect of the present invention, there is provided an information processing method, including a comparison step of comparing first time information regarding an isochronization timing of isochronous transaction in a first environment and second time information regarding an isochronization timing of isochronous transaction in a second environment with each other, and a transmission step of transmitting a result of the comparison by the comparison step to another information processing apparatus of the second environment.
According to a further aspect of the present invention, there is provided a providing medium which provides a computer-readable program for causing an information processing apparatus to execute a process including a comparison step of comparing first time information regarding an isochronization timing of isochronous transaction in a first environment and second time information regarding an isochronization timing of isochronous transaction in a second environment with each other, and a transmission step of transmitting a result of the comparison by the comparison step to another information processing apparatus of the second environment.
In the information processing apparatus, information processing method and providing medium described above, first time information regarding an isochronization timing of isochronous transaction in the first environment and second time information regarding an isochronization timing of isochronous transaction in the second environment are compared with each other, and a result of the comparison is transmitted to another information processing apparatus of the second environment. Consequently, for example, where isochronous transaction is to be performed between a wire environment and a radio environment, time information regarding an isochronization timing in the wire environment can be reflected on time information regarding an isochronization timing in the radio environment. Therefore, matching of isochronism between the two environments can be maintained.
According to a still further aspect of the present invention, there is provided an information processing apparatus, comprising a reception means for receiving comparison information between first time information regarding an isochronization timing of isochronous transaction in a first environment and second time information regarding an isochronization timing of isochronous transaction in a second environment, the comparison information being transmitted from another information processing apparatus, a correction means for correcting time information of the information processing apparatus in response to the comparison information received by the reception means, and a time management means for performing time management of the second environment in accordance with the time information corrected by the correction means.
According to a yet further aspect of the present invention, there is provided an information processing method for an information processing apparatus, having a reception step of receiving comparison information between first time information regarding an isochronization timing of isochronous transaction in a first environment and second time information regarding an isochronization timing of isochronous transaction in a second environment, the comparison information being transmitted from another information processing apparatus, a correction step of correcting time information of the information processing apparatus in response to the comparison information received by the reception step, and a time management step of performing time management of the second environment in accordance with the time information corrected by the correction step.
According to a yet further aspect of the present invention, there is provided a providing medium which provides a computer-readable program for causing an information processing apparatus to execute a process having a reception step of receiving comparison information
Hiraiwa Hisaki
Tanimoto Erika
Gaffin Jeffrey
Mai Rijue
Maioli Jay H.
Sony Corporation
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