log Floating Point Logarithm

Library:

Floating Point Arithmetic

Behavior

This component calculates one of four floating-point logarithmic functions, selected by the Logarithm Mode attribute. The result is rounded to the selected floating-point size.

Arbitrary base

Calculates the logarithm of the upper west input x using the lower west input y as its base. The implementation evaluates ln(x) / ln(y).

Natural logarithm

Calculates ln(x) from the single west input.

Logarithm with base 10

Calculates log₁₀(x) from the single west input.

Natural logarithm of (input + 1)

Calculates ln(1 + x) from the single west input. This mode preserves better numerical accuracy than adding 1 before taking the logarithm when x is close to zero.

The ERR output is 1 when the result is NaN and 0 otherwise. An input containing unknown or error bits is converted to NaN. Other floating-point results, including positive or negative infinity, do not set ERR.

Pins

West edge, north end (input, bit width matches Float size)

The value x in Arbitrary base mode.

West edge, south end (input, bit width matches Float size)

The logarithm base y. This pin is present only in Arbitrary base mode.

West edge, center (input, bit width matches Float size)

The value x in any single-input logarithm mode.

East edge (output, bit width matches Float size)

The selected logarithmic result.

South edge (output, bit width 1)

ERR: 1 if the result is NaN; otherwise 0.

Attributes

Poke Tool Behavior

None.

Text Tool Behavior

None.

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