| 摘要 |
PURPOSE:To efficiently and rationally constitute an electronic circuit of large scale by mixing a parallel and serial scan systems in one electronic circuit according to the condition of the quantity of a hardware such as a signal line or a gate line. CONSTITUTION:A scan distribution circuit is provided for the interface circuit of a scan circuit corresponding to respective state holding circuits. In order to apply a scan address to the state holding circuit according to the parallel scan system, a serial/parallel converting circuit is disposed. The address information of serial data steps a shifter counter 10 to decode the value in a decoder 11 and form a parallel scanning address. According to a scan circuit selecting signal formed in a decoder 12, one group of the state holding circuit groups is selected to be scanned. When the selected scan circuit is a serial scan circuit, the address information of inputted serial data is inputted to the relevant serial scan circuit without being converted. |
