3. Instruction Set
API
Mnemonic Operands Function
SS2
SX2
21 D
SUB P
Subtraction
Type
OP
Bit Devices Word devices Program Steps
X Y M S K H KnX
KnY
KnM
KnS
T C D E F
SUB, SUBP: 7 steps
DSUB, DSUBP: 13 steps
SS2
SX2
SS2
SX2
SS2
SX2
Operands:
S
1
: Minuend S
2
: Subtrahend D: Remainder
Explanations:
1. This instruction subtracts S
1
and S
2
in BIN format and stores the result in D
2. The MSB is the sign bit. 0 indicates positive and 1 indicates negative. All calculation is
algebraically processed.
3. If S
1
, S
2
and D use device F, only 16-bit instruction is applicable.
4. Flags: M1020 (Zero flag), M1021 (Borrow flag), M1022 (Carry flag). The flag operations of
ADD instruction can also be applied to the subtract instruction.
Program Example 1:
In 16-bit BIN subtraction:
When X0 = ON, the content in D0 will minus the content in D10 and the results will be stored in
D20
Program Example 2:
In 32-bit BIN subtraction:
When X10 = ON, the content in (D31, D30) will minus the content in (D41, D40) and the results will
be stored in (D51, D50). D30, D40 and D50 are low word; D31, D41 and D51 are high word
(D31, D30) − (D41, D40) = (D51, D50)