You can create custom controls of supported data types and select these controls as data types for FPGA register items, memory items, FIFOs, and handshake items. The custom control you select as a data type in the Register Properties, Memory Properties, FIFO Properties, or Handshake Properties dialog boxes can be any control, type definition (typedef), or strict typedef created with supported data types. If the custom control is a typedef or strict typedef, LabVIEW disconnects the control from the typedef.

Using custom data types has the following advantages:

• Simplifies block diagrams and can increase application throughput.
• For some FPGA targets, breaks the 64-bit barrier by joining two small supported types into one larger data type. Refer to the specific FPGA target hardware documentation for more information about supported data types.
• Keeps resources separate for each value in the FIFO or memory.

Combining Smaller Data Types While Keeping Resource Identities Separate

In the following example, the FIFO can transfer both address and data information in a single cluster element. Using a custom control, these values remain distinct so that you can split the values after reading the element from the FIFO.

Caveat when Using Custom Controls

Using large custom controls can affect the performance of an FPGA VI or waste FPGA resources.