Multifunctional scan flip-flop
AssigneeKabushiki Kaisha Toshiba
InventorsSoichi Kawasaki, Takashi Yoshimori, Keiji Matsumoto
Life of this patent
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Abstract
A multifunctional scan flip-flop having a normal function and a scan function, including: a first latch used for a normal function for latching input data applied to a data input terminal during a normal function operation, the latch operation being carried out synchronous with a clock applied to a clock input terminal; a second latch used for a scan function for holding scan data applied to a scan data input terminal during a scan function operation; and a delay circuit for delaying one of the input data and the clock relative to the other, the delay operation being carried out in accordance with the H/L level of the scan data held by the second latch.
Claims11
A multifunctional scan flip-flop having a normal function and a scan function, comprising:
- a first latch used for a normal function for latching input data applied to a data input terminal during a normal function operation, said latch operation being carried out synchronous with a clock applied to a clock input terminal;
- a second latch used for a scan function for holding scan data applied to a scan data input terminal during a scan function operation;
- and
- delay means for delaying one of said input data and said clock relative to the other, said delay operation being enabled/disabled responsive to the H/L level of said scan data held and outputted by said second latch.
A multifunctional scan flip-flop having a normal function and a scan function, comprising:
- input data selecting means for selecting and outputting one of a plurality of applied input data in accordance with a selection data;
- a first latch for latching input data outputted from said input data selecting means, said latch operation being carried out in synchronous with a clock applied to a clock input terminal;
- and
- a second latch for holding data applied to a scan data input terminal, said latch operation being carried out in synchronism with another clock, and said held data being outputted as said selection data.
A multifunctional scan flip-flop having a normal function and a scan function, comprising:
- a first latch for latching input data applied to a data input terminal and outputting said input data and the inverted data of said input data, said latch operation being carried out synchronous with a clock applied to a clock input terminal;
- a second latch for holding data applied to a scan data input terminal, said hold operation being carried out in synchronism with said clock, and said latched data being outputted as a selection data;
- and
- output data selecting means for selecting and outputting one of said input data and said inverted data respectively outputted from said first latch, in accordance with said selection data.
Dependencies are inferred from the claim text.