Pin Sharing
Pin sharing is the way, how multiple beans can use one pin of the
CPU. Processor Expert supports the following ways of pin sharing: This bean supports reading of input pin signal without any previous pin
initialization. The feature can be used only if the pin (port) contains
RAW DATA register, which allows reading the input pin signal in any
settings of related peripherals. See bean documentation for more details.
Note: InputPin bean is included in the installation of Processor Expert
only if any target CPU supports the feature mentioned above. There is also possible to select pin sharing for the pin in the bean
inspector, which is shared with another bean (denoted "main"
bean). In this case the pin must be allocated and initialized by the main
bean. The shared bean provides CPU specific verification testing if pin
sharing is supported on target CPU with the main bean and decides, if the
sharing can be set in the initialization (design- time sharing), or if it
is necessary to invoke a method to select switch between main and shared
bean (run-time sharing). It's allowed to set sharing of one pin for
several beans as well. Pin sharing is advanced usage of the CPU peripherals and should be done
only by skilled users. Pin sharing allows advanced usage of the pins even
on small CPU packages and allows application-specific usage of the pins. Pin sharing can be set in the bean
inspector. The bean inspector must be switched into EXPERT mode,
and then the pin sharing button must be switched down. See picture, button
at the right side of the second column.
Design-time sharing does not need any user action in run-time.
Some CPUs support usage of the pin by more peripherals. For example input
pin can be used as an input for capture and at the same time as an input
for another counter (EventCounter). Design-time sharing is indicated by
single-color icon on the button Run-time sharing means, that it's necessary to invoke bean
method ConnectPin to connect bean to the shared pin. And it's necessary to
invoke main bean method to connect pin back to main bean. In fact the bean
can usually operate simultaneously, but they have no connection to the
shared pins unless ConnectPin method is executed. Run-time sharing is
indicated by three-color icon on the button If more beans share one pin, it's better to invoke method ConnectPin
before any bean usage. It's allowed to invoke this method also during
design-time sharing - the method has no effect in this case. The method
ConnectPin is not generated by default and it must be turned on manually. Shared pins are presented in the Target CPU
view as well. The bean to pin connection line is red.InputPin bean
Design-Time and Run-Time Sharing
Figure 1 - Pin Sharing
Button
