Detecting Input Events; Input Event Mask Register, Bit Map; Input Event Polarity Register, Bit Map; Input Status Register, Bit Map - PEP CP381 Manual

CP381
4.3.4

Detecting Input Events

Detecting events on input means that the CP381 hardware can supervise the input ports upon
their changing state and without being continuously polled. This mode is controlled by three
control registers. In the Input Event Mask Register, individual input events can be enabled
which should be monitored. In the Input Polarity Register the direction of the change-of-state
is set. Detected events are reported in the corresponding Input Event Status Register.
Table 4-6: Input Event Mask Register, Bit Map
Bits Type
31-30 r/w
29 - 0 r/w
Note...
A set bit means that event detection is disabled for the corresponding input port.
Table 4-7: Input Event Polarity Register, Bit Map
Bits Type
31-30 r/w
29 - 0 r/w
Note...
A bit setting of 0 bit means that an event is detected when the input port
changes from 0 to 1 whereas a setting of 1 means that an event is detected
when the input changes from 1 to 0.
Table 4-8: Input Status Register, Bit Map
Bits Type
31 r/w
30 r/w
29 - 0 r/w
Note...
A set bit means that an event was detected on the corresponding input port.
Events must be cleared by writing a "1" to the corresponding input event flag.
Otherwise, consecutive events on the same input would no longer be detected.
ID 24107, Rev. 01
Default
0 Not used
1 Input event mask bits
Default
0 Not used
0 Input event polarity bits
Default
0 Input latch-on-event status flag
0 Input compare status flag
0 Input event status flags
© 2002 PEP Modular Computers GmbH
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