Chapter 5 Instruction Specifications
5-50
Item number Arithmetic instructions-5 Name BCD subtraction (BCD SUBTRACTION)
Ladder format Condition code
Processing time (µs)
Remark
R7F4 R7F3 R7F2 R7F1 R7F0
Average Maximum
d = s1 B– s2 DER ERR SD V C Upper case: W
↕
zzz
↕
104
Lower case: DW
Instruction format Number of steps
Condition Steps
d = s1 B– s2 Word 4 163
Double word 6
Bit Word Double word
Usable I/O
XY
R,
M
TD, SS,
WDT, MS,
TMR, CU,
RCU, CT WX WY
WR,
WM TC DX DY
DR,
DM
Constant
Other
d Substitution destination {{{ {{
s1 Minuend {{{{{{{{
s2 Subtrahend {{{{{{{{
Function
• Subtracts s2 from s1 as the BCD data, and substitutes the result into d as the BCD data.
• The C flag is set to “1” if there is a digit decrease, and “0” if not.
• The DER flag is set to “1” if s1 or s2 is not a valid BCD data. If so, operation is not performed and the C flag retains the
previous state without outputting to d. If the s1 and s2 are valid BCD data, the DER is set to “0.”
Notes
• The combinations of d, s1 and s2 are as follows:
ds1s2
Word Word Word
Double word Double word Double word
Program example
X00000
WR0003= WR0004 B- WR0005
LD X00000
[
WR0003 = WR0004 B- WR0005
]
Program description
• When input X00000 is on, the difference between WR0004 value and WR0005 value is substituted into WR0003 as BCD
data.
d = s1 B– s2
