| 摘要 |
PURPOSE: An input variation sensing circuit is provided to be capable of improving an integration density and securing a stable output with regard to external variation, by digitizing circuits. CONSTITUTION: A buffer input part(11) judges whether externally applied pin values(Pin_In) satisfy wake-up conditions(WUC). When the externally applied pin values(Pin_In) do not satisfy wake-up conditions(WUC), the buffer input part(11) outputs a set/reset signal(B) for disabling an output of a corresponding pin. When the externally applied pin values(Pin_In) satisfy wake-up conditions(WUC), the buffer input part(11) outputs a signal(A) to the pin values(Pin_In). A sleep mode pin value latch circuit part(12) consists of the first and second latch circuit parts. The first latch circuit part is set by the set/reset signal(B) so as to output a high signal when the externally applied pin values(Pin_In) do not satisfy wake-up conditions(WUC). The first latch circuit part is enabled by an external latch enable signal(C) to output as a signal(D) a low level of the signal(A) during a period when the externally applied pin values(Pin_In) satisfy wake-up conditions(WUC). The second latch circuit part is reset by the set/reset signal(B) to output a low signal when the externally applied pin values(Pin_In) do not satisfy wake-up conditions(WUC), and outputs as a signal(E) a high value of the signal(A) during a sleep mode after enabled by the latch enable signal(C). A pin value variation sensing part(13) outputs a wake-up signal in response to the signals(D,E,A).
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