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Publication 1747-RM001G-EN-P - November 2008

Math Instructions 4-31

Natural Log (LN)

Use the LN instruction to take the natural log of the value in the source and

store the result in the destination. The source must be greater than zero. The

resulting value in the destination is always greater than or equal to -87.33654

and less than or equal to 88.72284. Use this instruction with SLC 5/03

(OS302), SLC 5/04 (OS401), and SLC 5/05 processors.

Updates to Arithmetic Status Bits

The arithmetic status bits are found in Word 0, bits 0 to 3 in the status file.

After an instruction is executed, the arithmetic status bits in the status file are

updated.

Log to the Base 10 (LOG)

Use the LOG instruction to take the log base 10 of the value in the source and

store the result in the destination. The source must be greater than zero. The

resulting value in the destination is always greater than or equal to -37.92978

and less than or equal to 38.53184. Use this instruction with SLC 5/03

(OS302), SLC 5/04 (OS401), and SLC 5/05 processors.

Updates to Arithmetic Status Bits

The arithmetic status bits are found in Word 0, bits 0 to 3 in the status file.

After an instruction is executed, the arithmetic status bits in the status file are

updated.

Natural Log

Source N7:45

Dest N7:46

Output Instruction

Fixed SLC

5/01

SLC

5/02

SLC

5/03

SLC

5/04

SLC

5/05

•••

Table 4.21 Processor Function

With this Bit The Processor

S:0/0 Carry (C) always resets.

S:0/1 Overflow (V) sets if an overflow is generated or an unsupported input is

detected; otherwise resets.

S:0/2 Zero (Z) sets if the result is zero; otherwise resets.

S:0/3 Sign (S) sets if the result is negative; otherwise resets.

LOG

Log Base 10

Source N7:47

Dest N7:48

LOG