| 摘要 |
PROBLEM TO BE SOLVED: To surely prevent malfunctions in a vendor test mode by signal input errors or noise. SOLUTION: In setting a vendor test mode, a command signal is inputted to a specified input terminal, a mode setting signal is inputted to an address terminal, and a vendor test setting signal TS is inputted to a specified address terminal Aa. In a vendor test signal determination circuit 15, a set signal AaSV becomes a Hi signal, only when the vendor test set signal TS is Vcc+ΔV or more, and a mode selecting circuit 18 recognizes that the vendor test mode has been set, based on this set signal AaSV and the mode setting signal, and outputs a selection signal to select the vender test mode. |
