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US 5,961,616 AGranted
Data transfer system
AssigneeOki Data Corporation
InventorsNobuo Wakasugi, Tadashi Kasai, Hiroshi Sakaino, Hiroshi Okada
Life of this patent
Estimating the term…
Abstract
A data transfer system includes a host which provides a timing signal and data at an output, and a peripheral device which receives the timing signal and data from the host output, and produces an internal timing signal based on detection of a change in either the data or the polarity of the timing signal provided by the host.
Claims24
A data transfer system, comprising:
- a host system;
- and
- a peripheral unit;
- wherein the host system transfers data and a host strobe signal to the peripheral unit;
- wherein the host system includes strobe signal inverting means for determining whether the content of data being currently transferred is the same as the content of previously transferred data, and for inverting the host strobe signal when the content of the data is being currently transferred is determined to be the same as the content of the previously transferred data;
- wherein the peripheral unit includes:
- internal generation means for
- (a) generating an internal strobe signal responsive to a change in the received transferred data and
- (b) generating the internal strobe responsive to a transition of the host strobe signal;
- latching means for latching the received transferred data in response to the internal strobe signal;
- a buffer for temporarily storing the data and host strobe signal transferred by the host system;
- and
- means for generating a synchronization signal at a time that the data and the strobe signal are stored in said buffer;
- wherein said internal generation means comprises:
- a first data buffer for receiving and storing transferred data in successive units;
- a second data buffer for receiving and storing the transferred data stored in the first data buffer after a delay;
- a data change detection circuit for detecting a data change by comparing the data stored in the first data buffer and the data stored in the second data buffer to generate a data change output,
- a first strobe signal buffer for successively receiving and storing a value of the host strobe signal;
- a second strobe signal buffer for receiving and storing the value of the host strobe signal from the first strobe signal buffer after a delay;
- a strobe change detection circuit for detecting a strobe signal change by comparing the value of the strobe signal stored in the first strobe signal buffer and the value of the host strobe signal stored in the second strobe signal buffer to generate a strobe change output;
- and
- a logic circuit for receiving the data change output and the strobe change output and producing an internal strobe signal;
- wherein the peripheral unit further comprises:
- a first-in first-out receiving buffer for receiving transferred data;
- capacity means for determining a current capacity of the receiving buffer;
- status means for detecting a status in which the current capacity exceeds a given value;
- and
- not busy means for providing the detected status to the host system as a not busy signal;
- wherein the host system transfers an amount of data equal to the given value in response to the not busy signal;
- wherein the peripheral unit has at least three operation modes including:
- an idle mode during which the peripheral unit waits for a change in the transferred data,
- a transient mode during which the transferred data is in a process of changing, and
- a settling mode during which the peripheral unit waits for a first given time interval to pass subsequent to termination of a change in the transferred data;
- and
- wherein the peripheral unit further comprises:
- control means for:
- (1) shifting the peripheral unit to the transient mode upon detection of a change in the transferred data during the idle mode,
- (2) shifting to the settling mode at a point in time when a change in the transferred data is no longer present during the transient mode,
- (3) returning to the transient mode upon detection of a change in the transferred data during the settling mode, and
- (4) causing production of the internal strobe signal after a second given time interval has passed in the settling mode;
- and
- timing means for determining given time intervals.
39 more elements
A data transfer system comprising:
- a host system;
- and
- a peripheral unit;
- wherein the host system transfers data and a strobe signal to the peripheral unit;
- wherein the host system includes interface switching mode signal generating means for:
- switching operation of the host system between:
- (a) a Centronics interface mode in which the strobe signal is transferred for each transfer of data, and
- (b) a data change synchronized interface mode in which a determination is made to see if currently transferred data is the same as previously transferred data, and
- inverting the strobe signal when currently transferred data is the same as previously transferred data;
- and
- wherein the peripheral unit comprises:
- means for inhibiting data sampling after an initial change in the transferred data during a mode conversion from the Centronics interface mode to the data change synchronized interface mode;
- and
- means for inhibiting data sampling in response to a change in the strobe signal during a mode conversion from the data change synchronized interface mode to the Centronics interface mode.
11 more elements
A data transfer system, comprising:
- a host system;
- and
- a peripheral unit;
- wherein the host system transfers data and a host strobe signal to the peripheral unit;
- wherein the host system includes strobe signal inverting means for determining whether the content of data being currently transferred is the same as the content of previously transferred data and for inverting the host strobe signal when the content of the data is being currently transferred is determined to be the same as the content of the previously transferred data;
- wherein the peripheral unit includes:
- internal generation means for
- (a) generating an internal strobe signal responsive to a change in the received transferred data, and
- (b) generating the internal strobe responsive to a transition of the host strobe signal;
- latching means for latching the received transferred data in response to the internal strobe signal:
- a buffer for temporarily storing the data and host strobe signal transferred by the host system;
- and
- means for generating a synchronization signal at a time that the data and the strobe signal are stored in said buffer;
- wherein said internal generation means comprises:
- a first data buffer for receiving and storing transferred data in successive units;
- a second data buffer for receiving and storing the transferred data stored in the first data buffer after a delay;
- a data change detection circuit for detecting a data change by comparing the data stored in the first data buffer and the data stored in the second data buffer to generate a data change output;
- a first strobe signal buffer for successively receiving and storing a value of the host strobe signal;
- a second strobe signal buffer for receiving and storing the value of the host strobe signal from the first strobe signal buffer after a delay;
- a strobe change detection circuit for detecting a strobe signal change by comparing the value of the strobe signal stored in the first strobe signal buffer and the value of the host strobe signal stored in the second strobe signal buffer to generate a strobe change output;
- and
- a logic circuit for receiving the data change output and the strobe change output and producing an internal strobe signal;
- wherein the peripheral unit further comprises:
- a receiving buffer for receiving transferred data;
- capacity means for determining a current capacity of the receiving buffer;
- comparing means for comparing the determined current capacity of the receiving buffer with a predetermined value to produce a comparison signal;
- and
- busy means for providing a busy status to the host based on the comparison signal;
- wherein the host system successively transfers an amount of data equal to the predetermined value based on the busy status;
- and
- wherein the internal generation means generates the internal strobe signal responsive to the transition of the host strobe signal in a first direction, and also responsive to the transition of the host strobe signal in a second direction.
28 more elements
A data transfer system comprising:
- a host which provides a timing signal and data at an output thereof;
- and
- a peripheral device which includes
- a buffer for temporarily storing the data and host strobe signal transferred by the host system;
- and
- means for generating a synchronization signal at a time that the data and the strobe signal are stored in said buffer;
- and
- wherein the peripheral device
- receives the timing signal and data from the host output,
- produces an internal timing signal on detection of a change in the data,
- produces the internal timing signal on detection of a change in a polarity of the timing signal provided by the host, and
- latches the data from the host output responsive to the produced internal timing signal.
9 more elements
Dependencies are inferred from the claim text.