Omron SYSMAC CJ - REFERENCE MANUAL 08-2008 Reference Manual page 731

Double-precision Floating-point Instructions (CS1-H, CJ1-H, CJ1M, or CS1D Only)
Description
Area
Indirect DM/EM
addresses in binary
Indirect DM/EM
addresses in BCD
Constants
Data Registers
Index Registers
Indirect addressing
using Index Registers
LOGD(859) calculates the natural (base e) logarithm of the double-precision
(64-bit) floating-point number in words S to S+3 and places the result in words
D to D+3.
log
S+3
e
The source data must be positive; if it is negative, an error will occur and the
instruction will not be executed.
If the absolute value of the result is greater than the maximum value that can
be expressed as floating-point data, the Overflow Flag will turn ON and the
result will be output as
Note The constant e is 2.718282.
The following diagram shows the relationship between the input data and
result.
S
@ D00000 to @ D32767
@ E00000 to @ E32767
@ En_00000 to @ En_32767
(n = 0 to C)
*D00000 to *D32767
*E00000 to *E32767
*En_00000 to *En_32767
(n = 0 to C)
---
---
---
,IR0 to ,IR15
–2048 to +2047 ,IR0 to –2048 to +2047 ,IR15
DR0 to DR15, IR0 to IR15
,IR0+(++) to ,IR15+(++)
,–(– –)IR0 to, –(– –)IR15
S+2 S+1 S D+3
.
R
S: Input data
R: Result
Section 3-16
D
D+2 D+1 D
691