| 摘要 |
TCK regulation apparatus of a boundary scan architecture selectively changes TCK being applied to a boundary scan input/output cell. The TCK regulation apparatus includes: a shift register for sequentially shifting a plurality of shift cells; a second update register for updating an output of the shift register; a combination circuit for partially combining the output of the second update register, and generating a plurality of selection signals; a signal generator for applying an original shift register clock to a boundary scan register when a counted TCK value is reached to a set count value; a third multiplexer for selectively generating an output of the first boundary scan output or an output of the second multiplexer; a fourth multiplexer for selectively generating an output of the second boundary scan cell and an output of the 3-state buffer; a fifth multiplexer for selectively generating an output of TDI and an output of the first boundary scan cell; and a sixth multiplexer for selectively generating an output of the third multiplexer and an output of the second multiplexer; and a seventh multiplexer for selectively generating an output of the fourth multiplexer and an output of the 3-state buffer.
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