2.1.1 Ports
Port components represent the interface between a hierarchical layer and the layer above and are strictly input or output.
An input port is an input to the CLB:
An output port is an output from the CLB:
- I/O ports (Global)
- Off-sheet ports (hierarchical)
Global Input Ports
Global I/O ports represent the interface to other peripherals on the MCU. To place an input port, drag and drop the input port symbol onto the canvas and select the I/O option in the Properties panel.
Input ports from other peripherals have one of four synchronizer options selected in the Input Synchronizer options box. For more information, see Input Synchronizers.
Input ports from the CPU do not have synchronizer options. For more information, see Using CLBSWIN.
Usually, the global ports are used only at the top level (main), but there are cases in which it makes sense to use global input ports on sub-sheets. It is also possible to use the same input signal with an alternative synchronizer option - in which case a second input port symbol must be used, and the alternative synchronizer option applied to that input.
Global output ports
To place an output port, drag and drop the output port symbol onto the canvas and select the I/O option in the Properties panel.
Off-Sheet I/O Ports
For more information on hierarchical design, see Using Hierarchical Modules.