High Throughput Exponential

Specifies general information about this function.

• Fixed-Point Configuration—Specifies the encodings, word lengths, and integer word lengths of the input and output terminals of this function. The configurations you specify determine the value range of the terminals.
  • x Type—

    Specifies the fixed-point configuration of the x input terminal.

    If you wire a fixed-point data type to this terminal and that data type follows the rules for this terminal, LabVIEW dims this section and uses information from the wire. If you wire a fixed-point data type to this terminal that does not follow the rules, LabVIEW breaks the wire.

    • Signed—Specifies that this terminal is signed.
    • Unsigned—Specifies that this terminal is unsigned.
    • Word length—Specifies the word length of this terminal.
    • Integer word length—Specifies the integer word length of this terminal. If the encoding is Signed, the maximum value is 1 bit. If the encoding is Unsigned, the maximum value is 0 bits.
  • exp(x) Type—

    Specifies the fixed-point configuration of the exp(x) output terminal.

    • Signed—Specifies that this terminal is signed. exp(x)) always is positive, so LabVIEW sets the encoding to Unsigned and dims this option.
    • Unsigned—Specifies that this terminal is unsigned. exp(x)) always is positive, so LabVIEW sets the encoding to Unsigned and dims this option.
    • Word length—Specifies the word length of this terminal. The value must be between 4 and 64 bits.
    • Integer word length—Specifies the integer word length of this terminal. LabVIEW sets this value to 2 bits and dims this option.
  • Rounding mode—

    Specifies how this function rounds the output data if rounding is necessary. You can choose Truncate (default), Round Half-Up, or Round Half-Even. If rounding occurs, the option you choose might affect the amount of resources this function requires.

• Execution Mode—Specifies how this function executes.
  • Outside single-cycle Timed Loop—Configures this Express VI to execute outside a single-cycle Timed Loop.

    If you select this option and place this Express VI inside a single-cycle Timed Loop, the Code Generation Errors window reports an error when you compile the FPGA VI.

  • Inside single-cycle Timed Loop—Configures this Express VI to execute inside a single-cycle Timed Loop.

    If you select this option and place this Express VI outside a single-cycle Timed Loop, the Code Generation Errors window reports an error when you compile the FPGA VI.

  • Throughput—Specifies the minimum number of cycles between two successive values of valid input data. Entering a low value in this control results in a high throughput rate. The maximum value of Throughput depends on the Value of the Number of internal iterations, which you specify on the CORDIC Details page.

    Throughput is available only if you select Inside single-cycle Timed Loop.

    If you select Outside single-cycle Timed Loop, this function returns a valid result on every call to the function. Therefore, the Throughput control displays 1 call / sample. The Configuration Feedback indicator displays the number of clock cycles this function takes to return a valid result.

• Registers—Specifies whether to add internal registersfor function inputs and/or outputs. These registers will be placed outside of any embedded resources, such as block multipliers or DSP48E slices. This section is available only if you select Inside single-cycle Timed Loop.
  Note Adding registers can reduce the length of the combinatorial path, which can prevent compilation errors that result from a long combinatorial path. However, adding registers also increases the latency of this function, which means this function takes additional clock cycles to return a valid result.
  • Register inputs—Adds internal registers after the inputs to this function. Selecting this option increases the latency of the function by one cycle.
  • Register outputs—Adds internal registers before the outputs of this function. Selecting this option increases the latency of the function by one cycle.

• Precision—Specifies options about the precision of the result(s) this function returns.
  • Number of internal iterations—Specifies the number of cycles this function takes to return a valid result without considering input/output registers.
    • Adapt to configuration—Specifies whether LabVIEW automatically determines the number of internal iterations based on the options you specify on the General page. By default, this checkbox contains a checkmark.
    • Value—Specifies the number of cycles this function takes to return a valid result without considering input/output registers. By default, LabVIEW dims this control and automatically determines this value based on the options you specify on the General page.

      To enable this control, remove the checkmark from the Adapt to configuration checkbox. Increasing the number of internal iterations increases both the precision of the result and the latency of this function.

  • Internal word length—Specifies the word length of internal calculations.
    • Adapt to configuration—Specifies whether LabVIEW automatically determines the number of internal iterations based on the options you specify on the General page and the Value of the Number of internal iterations. By default, this checkbox contains a checkmark.
    • Value—Specifies the word length of internal calculations. By default, LabVIEW dims this control and automatically determines this value based on the options you specify on the General page and theValue of theNumber of internal iterations.

      To enable this control, remove the checkmark from the Adapt to configuration checkbox. Increasing the number of internal iterations increases both the precision of the result and the latency of this function.

x —

Specifies the input to this function. x must be in the range [–1, 1).

input valid —

Specifies whether the next data point has arrived for processing. Wire the output valid output of an upstream node to this input valid to transfer data from the upstream node to this Express VI.

To display this handshaking terminal, select the Inside single-cycle Timed Loop in the configuration dialog box.

ready for output —

Specifies whether downstream nodes are ready for this Express VI to return a new value. The default is TRUE. Use a Feedback Node to wire the ready for input of a downstream node to ready for output of the current node.

Note If ready for output is FALSE during a given cycle, the output valid terminal returns FALSE during that cycle.

To displayready for output, select the Inside single-cycle Timed Loop in the configuration dialog box.

exp(x) —

Returns e raised to the power of x.

output valid —

Returns TRUE if this node has computed a result that downstream nodes can use. Use output valid for handshaking with other FPGA VIs and functions.

To display this terminal, select the Inside single-cycle Timed Loop in the configuration dialog box.

ready for input —

Returns TRUE if this node is ready to accept new input data. Use a Feedback Node to wire ready for input to ready for output of an upstream node.

Note If ready for input returns FALSE during a given cycle, LabVIEW discards any data that other nodes send to this node during the following cycle. LabVIEW discards this data even if the input valid terminal is TRUE during the following cycle.

To display ready for input, select the Inside single-cycle Timed Loop in the configuration dialog box.