ST10 FAMILY PROGRAMMING MANUAL
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SUBB
Integer Subtraction
Syntax
SUBB op1,
op2
Operation
(op1)
<-- (op1) - (op2)
Data Types
BYTE
Description
Performs a 2’s complement binary subtraction of the source operand specified by op2 from the destina-
tion operand specified by op1. The result is then stored in op1.
Flags
Addressing Modes
E
Z
V
C
N
*
*
*
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. Cleared otherwise.
V
Set if an arithmetic underflow occurred, ie. 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
SUBB
Rb
n
, Rb
m
21 nm
2
SUBB
Rb
n
, [Rw
i
]
29 n:10ii
2
SUBB
Rb
n
, [Rw
i
+]
29 n:11ii
2
SUBB
Rb
n
, #data
3
29 n:0###
2
SUBB
reg, #data
16
27 RR ## ##
4
SUBB
reg, mem
23 RR MM MM
4
SUBB
mem, reg
25 RR MM MM
4
Summary of Contents for ST10 Series
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