MCC iPort/USB 2, Руководство пользователя

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on configuring the I
2
C Bus interface.
I
2
C Bus Mini Interface Receptacle
Mini Interface Receptacle Pinout
I
2
C Bus Mini-Clip-Lead cables are available to connect the iPort/USB 2 adapter to a
target system. Each clip-lead is identified (White=C=SCL, Red=V=+V,
Green=D=SDA, Black=G=Ground, Gray=(no mark)=/INTerrupt).
I
2
C Bus Mini-Interface cables with two Mini Interface plugs are also available to
connect the I
2
C adapter to an external I
2
C Bus.
2.3 /INTerrupt Signal
The /INTerrupt signal is an extra pin found on some I
2
C devices. The /INT signal
allows a slave-only device to attract the attention of a bus master device by
lowering the /INT signal to a logical low voltage level.
The iPort/USB 2 provides an open-collector /INT signal which can be connected to
a corresponding pin on a bus master or slave device. The /INT signal allows the
iPort/USB 2 to participate in interrupt signaling between master or slave devices.
The iPort/USB 2 generates an I
2
C Bus interrupt assert (/INT=low) upon receiving
an iNterrupt Assert command from the host computer. The interrupt signal is
released (/INT = high) when the iPort/USB 2 is addressed as an I
2
C Bus slave
device, or an iNterrupt Release command is received from the host computer.
Interrupt monitoring is enabled upon receiving an Enable /INT Monitor command
from the host computer. Interrupt monitoring causes the iPort/USB 2 to monitor the
/INT signal level, and automatically send a notification to the host computer when
the /INT signal changes state.