摘要 |
There are provided a boundary scan element including a plurality of input-terminal-side boundary cells connected in series and assigned individually to respective input terminals, a plurality of output-terminal-side boundary cells connected in series and assigned individually to respective output terminals, a TAP circuit for controlling input and output of data to or from the input-terminal-side and output-terminal-side boundary cells, a TDI terminal for inputting serial data to be provided to the boundary cells, a TDO terminal for outputting data from the boundary cells as serial data, a TCK terminal to which a clock signal is input, and a TMS terminal to which a mode signal is input to switch an operation mode of the TAP circuit, characterized in that the input-terminal-side boundary cells and the output-terminal-side boundary cells are connected in parallel between the TDI terminal and the TDO terminal; and a communication system using the same. <IMAGE> |