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Symbol Math Instructions Section 3-10
Description –BC(416) subtracts BCD values in Su and CY from Mi and outputs the result
to R. If the result is negative, it is output to R as a 2’s complement.
Flags
Precautions If Mi and/or Su are not BCD, an error is generated and the Error Flag will turn
ON.
If as a result of the subtraction, the content of R is 0000 hex, the Equals Flag
will turn ON.
If an addition results in a borrow, the Carry Flag will turn ON.
Note To clear the Carry Flay (CY), execute the Clear Carry (CLC(041)) instruction.
Examples When CIO 0.00 is ON in the following example, D110 and CY will be sub-
tracted from D100 as 4-digit BCD values, and the result will be output to
D120.
3-10-16 DOUBLE BCD SUBTRACT WITH CARRY: –BCL(417)
Purpose Subtracts 8-digit (double-word) BCD data and/or constants with the Carry
Flag (CY).
Ladder Symbol
CY
R
CY
(BCD)
(BCD)
(BCD)
–
Mi
Su
CY will turn
ON when there
is a borrow.
Name Label Operation
Error Flag ER ON when Mi is not BCD.
ON when Su is not BCD.
OFF in all other cases.
Equals Flag = ON when the result is 0.
OFF in all other cases.
Carry Flag CY ON when the subtraction results in a borrow.
OFF in all other cases.
0.00
D100
D110
D120
–BCL(417)
R
Mi
Su
Mi: 1st minuend word
Su: 1st subtrahend word
R: 1st result word
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