SpinAsm LOG

LOG

Mnemonic	Operation	Instruction coding
LOG	C * LOG(|ACC|) + D	CCCCCCCCCCCCCCCCDDDDDDDDDDD01011

Description

LOG will multiply the Base2 LOG of the current absolute value in ACC with C and add the constant D to the result.

It is important to note that the LOG function returns a fixed point number in S4.19 format instead of the standard S.23 format, which in turn means that the most negative Base2 LOG value is –16.

The LOG instruction can handle absolute linear accumulator values from 0.99999988 to 0.00001526 which translates to a dynamic range of apx. 96dB.

D an offset to be added to the logarithmic value in the range of –16 to + 15.999998.

Parameters

Name	Width	Entry formats, range
C	16 Bit	Real (S1.14) Hex ($0000 ­ $FFFF) Symbolic
D	11 Bit	Real(S4.6) Symbolic

Syntax

LOG C, D

Coding Example

log  1.0,0