| 摘要 |
PROBLEM TO BE SOLVED: To detect a trigger using a JTAG circuit and return a semiconductor device from a power saving mode to a normal power mode.SOLUTION: ASIC 13a, 13b, and 13c each include a plurality of cells 39 and a shift register 41 to which these cells 39 are connected. A string constituted by signals stored in the plurality of cells 39 of the respective ASIC 13a, 13b, and 13c is referred to as one signal string. In a state in which no signals are input to any of a plurality of input/output terminals 31 of the respective ASIC 13a, 13b, and 13c, a string constituted by signals stored in the plurality of cells 39 of the respective ASIC 13a, 13b, and 13c is defined as an initial signal string. In a power saving mode, a process is performed to output a signal string from the three shift registers 41 connected in a daisy chain. If it is determined that the signal string does not match the initial signal string, it is determined that a trigger is detected. Power is then supplied to logical cores 35 of the respective ASIC 13a, 13b, and 13c. |
