Meilhaus Electronic ME-5100 cPCI, Manual, Page: 31 / 43

4.3.1 Bit-pattern Change
In the bit-pattern change mode, one or more bits that are to be
monitored for a change of state can be defined (masked). A
32-bit-wide argument per subdevice contains the mask. For each
input pin both one bit for rising edge and one bit for falling edge is
available. If the state of at least one bit masked with a “1” changes
(0 1 or 1 0), an interrupt is issued (see diagram 14 on
page 31).
In what is known as the “extended format” of interrupt handling
(see the ME-iDS manual), two bits are available for the interrupt
status of each pin. One is for the rising edge, and one for the
falling edge. The bits for the falling edges are assigned to the bit
b15…0, while the bits for the rising edges are assigned to the bits
b31…16.
Example (see diagram 14):
By writing the value 00800004 Hex as a mask value (see parame-
ter
<iIrqArg>
of the function bit 2 is monitored for
a falling edge, and bit 7 for a rising edge. A rising edge now is to
arrive at bit 7, so that an interrupt is issued and in the interrupt
status value bit b23 returns “1”. Any edges that might arrive at
pins labelled with an “X” are ignored. Only the change in state of a
pin whose edge is set to “1” in the parameter
<iIrqArg>
can is-
sue an interrupt.
The interrupt event is evaluated with the function
We recommend using what is known as the “extended format” to
obtain detailed information about the triggering edge.