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US 6,556,675 B2Granted
Subscriber line control device
AssigneeFujitsu Limited
InventorHisashi Koga
Life of this patent
Estimating the term…
Abstract
In a subscriber line control device connected to a plurality of subscriber circuits, there is a memory circuit for recording signal data indicating the states of subscriber lines, and hardware for displaying flags denoting changes in the signal data indicating the states of the subscriber lines, as well as firmware for monitoring periodically the flags displayed by the hardware.
Claims6
A subscriber line control device connected to a plurality of subscriber line circuits, comprising:
- a hardware including,
- a scan memory recording signal data for each of the plurality of subscriber line circuits,
- a comparator comparing received signal data of a subscriber line circuit with signal data recorded in the scan memory,
- a counter circuit counting times of disagreement between the compared signal data of the subscriber line circuit,
- a flag memory storing flags, indicating a change of signal data for each of the plurality of subscriber line circuits, and
- a memory write controller controlling to write the received signal data for updating the signal data previously stored in the scan memory and a flag, the flag indicating in the flag memory that the signal data have changed in the scan memory, when the times of disagreement between the compared signal data of the subscriber line circuit, counted by the counter circuit, reaches a predetermined number;
- and
- a firmware periodically monitoring the flag memory to detect the presence of the flag and reading out the signal data from the scan memory, of a subscriber line circuit corresponding to the detected flag.
5 more elements
A subscriber line control device connected to a plurality of subscriber line circuits, comprising:
- a hardware having a pair of active and standby systems and including in each of the active and standby systems,
- a scan memory recording signal data for each of the plurality of subscriber line circuits,
- a comparator comparing received signal data of a subscriber line circuit with signal data recorded in the scan memory,
- a counter circuit counting times of disagreement between the compared signal data of the subscriber line circuit,
- a flag memory storing flags, indicating a change of signal data for each of the plurality of subscriber line circuits, and
- a memory write controller controlling to write the received signal data for updating the signal data previously stored in the scan memory and a flag, the flag indicating in the flag memory that the signal data have changed in the scan memory, when the times of disagreement between the compared signal data of the subscriber line circuit, counted by the counter circuit reaches a predetermined number,
- wherein the memory write controller of the standby system periodically deletes flags written in the flag memory;
- and
- a firmware periodically monitoring the flag memory of the active system to detect the presence of the flag and reading out the signal data from the scan memory, of a subscriber line circuit corresponding to the detected flag.
6 more elements
A subscriber line control device connected to a plurality of subscriber line circuits, comprising:
- a control circuit including
- a scan memory recording signal data for each of the plurality of subscriber line circuits,
- a comparator comparing received signal data of a subscriber line circuit with signal data recorded in the scan memory,
- a counter circuit counting times of disagreement between the compared signal data of the subscriber line circuit and signal data recorded in the scan memory,
- a flag memory storing flags, indicating a change of signal data for each of the plurality of subscriber line circuits, and
- a memory write controller to control the writing of signal data into the scan memory and to control the writing of flags into the flag memory;
- and
- firmware periodically monitoring the flag memory to detect the presence of the flag and reading out the signal data from the scan memory of a subscriber line circuit corresponding to the detected flag, wherein
- when times of dissagreament between the compared signal data of the subscriber line circuit, counted by the counter circuit, reaches a predetermined number, the memory write controller controls the scan memory to write the received signal data thereby updating the signal data previously stored therein, and controls the flag memory to indicating that the stored signal data have changed.
6 more elements
Dependencies are inferred from the claim text.