ST10 FAMILY PROGRAMMING MANUAL
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SUBCB
Integer Subtraction with Carry
Syntax
SUBCB op1,
op2
Operation
(op1)
<-- (op1) - (op2) - (C)
Data Types
BYTE
Description
Performs a 2’s complement binary subtraction of the source operand specified by op2 and the previously
generated carry bit from the destination operand specified by op1. The result is then stored in op1. This
instruction can be used to perform multiple precision arithmetic.
Flags
Addressing Modes
E
Z
V
C
N
*
S
*
S
*
E
Set if the value of op2 represents the lowest possible negative number. Cleared otherwise.
Used to signal the end of a table.
Z
Set if result equals zero and the previous Z flag was set. Cleared otherwise.
V
Set if an arithmetic underflow occurred, i.e. the result cannot be represented in the specified
data type. Cleared otherwise.
C
Set if a borrow is generated. Cleared otherwise.
N
Set if the most significant bit of the result is set. Cleared otherwise.
Mnemonic
Format
Bytes
SUBCB
Rb
n
, Rb
m
31 nm
2
SUBCB
Rb
n
, [Rw
i
]
39 n:10ii
2
SUBCB
Rb
n
, [Rw
i
+]
39 n:11ii
2
SUBCB
Rb
n
, #data
3
39 n:0###
2
SUBCB
reg, #data
16
37 RR ## ##
4
SUBCB
reg, mem
33 RR MM MM
4
SUBCB
mem, reg
35 RR MM MM
4
Содержание ST10 Series
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