This topic contains FPGA-specific information about the objects on the Conversion Functions palette.

Note The information in this topic is subject to change with each version of the LabVIEW FPGA Module.

The following details apply to all the Conversion functions, except the Boolean Array to Number, Number To Boolean Array, To Fixed-Point, and To Single Precision Float functions.

Single-Cycle Timed Loop Supported.
Usage If you use this function with the single-precision floating-point data type, refer to the Using the Single-Precision Floating-Point Data Type and Deciding Which Data Type to Use in FPGA Designs topics for resource use, latency, and single-cycle Timed Loop support implications.
Timing The Conversion functions require no clock cycles to execute because they do not include internal registers. If you use the Conversion functions with the fixed-point data type, the overflow and rounding modes might impact timing.
Resources The Conversion functions consume no FPGA resources because they are purely wiring operations. If you use the Conversion functions with the fixed-point data type, the overflow and rounding modes might impact resources.
Boolean Array To Number
Single-Cycle Timed Loop Supported.
Usage The FPGA Module supports only one-dimensional arrays that resolve to a single size at compile time. The Boolean Array To Number function converts fixed-size arrays by default to use the smallest unsigned integer representation that will fit the array size.
Timing This function requires no clock cycles to execute because it does not include internal registers.
Properties Dialog Box The data type of number changes based on the size of the array when the Adapt to source checkbox in the Output Configuration page contains a checkmark. The following list describes the relationship between the array size and the data type of number:
  • If the array size is between 0 and 8, inclusive, number has a data type of U8.
  • If the array size is between 9 and 16, inclusive, number has data type of U16.
  • If the array is any other size, number has a data type of U32. For example, if Boolean array is a fixed-size array of size 9, number has a data type of U16.
  • If the number of elements in your array is between 33 and 64, inclusive, and you want all of them to be represented in the number, you must uncheck the Adapt to source checkbox. If the number of elements in your array exceeds 64, some of the elements from the array will not be represented in the number.
Resources This function consumes no FPGA resources because it is purely a wiring operation.
Number To Boolean Array
Single-Cycle Timed Loop Supported.
Usage

The LabVIEW FPGA Module supports only one-dimensional arrays that resolve to a single size at compile time. If LabVIEW cannot infer a single size for an array, you may need to manually configure the array to a fixed size.

You cannot wire an array or cluster to this function.
Timing This function requires no clock cycles to execute because it does not include an internal register.
Resources This function consumes no FPGA resources because it is purely a wiring operation.
To Fixed-Point
Single-Cycle Timed Loop Supported for fixed-point and integer inputs only.
Usage This function does not support array inputs. However, you can pass array data to this function element-by-element if you meet the following criteria:
  • You place the function inside a For Loop within a single-cycle Timed Loop
  • You enable auto-indexing on the For Loop tunnels
  • You use the function with other supported functions
  • You do not include shift registers or Feedback Nodes
Timing

This function requires no clock cycles for fixed-point and integer inputs if you select the Wrap overflow mode and Truncate rounding mode. Other overflow and rounding modes might impact timing.

This function requires multiple cycles to execute for single-precision floating-point inputs.
Resources

This function consumes no FPGA resources for fixed-point and integer inputs if you select the Wrap overflow mode and Truncate rounding mode. Other overflow and rounding modes might impact resources.

This function consumes significant FPGA resources when the input type is single-precision floating-point in order to scale the significand to the appropriate output type.
Notes You also can use the High Throughput To Fixed-Point function to perform fixed-point math and analysis on an FPGA target.
To Single Precision Float
Single-Cycle Timed Loop Not supported.
Usage N/A
Timing This function requires multiple cycles to execute for all input types.
Resources This function consumes significant FPGA resources in order to normalize fixed-point or integer values and compute their exponents. Resource usage is roughly proportional to the width of the input fixed-point or integer value.