Patent ID: 6591387
Filing Date: 2003-07-08
Classification: G01R

Abstract:
A communication system comprising:a plurality of boundary scan elements including input and output terminals, a plurality of boundary cells individually assigned to the respective input terminals and output terminals, a TAP circuit for controlling input and output of data to or from said boundary cells, a TDI terminal for inputting serial data to be supplied to said boundary cells, a TDO terminal for outputting data from said boundary cells in a form of serial data, a TCK terminal into which a clock signal is input, and a TMS terminal into which a mode signal for switching the operation mode of said TAP circuit is input; a plurality of data output units, each being connected in parallel with each of said boundary scan elements or provided with an IC into which each of the elements is incorporated; a communication controller connected with said boundary scan elements in series, said communication controller transmitting/receiving through said boundary scan elements control data for individually controlling said data output units; a signal data communication line connected with said data output units in parallel; and a signal processing unit connected with said signal data communication line and said communication controller for transmitting output data from said data output units under a control of said communication controller.