Omron SYSMAC CS Series, Reference Manual, Page: 731 / 1405

691
Double-precision Floating-point Instructions (CS1-H, CJ1-H, CJ1M, or CS1D Only)
Section 3-16
Description 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.
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.
Indirect DM/EM
addresses in binary @ D00000 to @ D32767
@ E00000 to @ E32767
@ En_00000 to @ En_32767
(n = 0 to C)
Indirect DM/EM
addresses in BCD *D00000 to *D32767
*E00000 to *E32767
*En_00000 to *En_32767
(n = 0 to C)
Constants ---
Data Registers ---
Index Registers ---
Indirect addressing
using Index Registers ,IR0 to ,IR15
–2048 to +2047 ,IR0 to –2048 to +2047 ,IR15
DR0 to DR15, IR0 to IR15
,IR0+(++) to ,IR15+(++)
,–(– –)IR0 to, –(– –)IR15
Area S D
S+1 S
→
S+3 S+2 D+1 D D+3 D+2
log
e
R
S: Input data
R: Result