Infineon Technologies C166S V2 User Manual page 310

SUBCB
Group
Syntax
Source Operand(s)
Destination Operand(s)
Operation
(op1) ← (op1) - (op2) - (C)
Description
Performs a 2s 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.
CPU Flags
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 word 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.
Encoding
Mnemonic
SUBCB Rb
SUBCB Rb
SUBCB Rb
SUBCB Rb
SUBCB mem , reg
SUBCB reg , #data8
SUBCB reg , mem
User Manual
Integer Subtraction with Carry
Arithmetic Instructions
SUBCB op1, op2
op1, op2 → BYTE
op1 → BYTE
E Z
* S
, #data3
n
, Rb
n m
, [Rw +]
n i
, [Rw ]
n i
Detailed Instruction Description
V C
* S
Format
39 n:0###
31 nm
39 n:11ii
39 n:10ii
35 RR MM MM
37 RR ## xx
33 RR MM MM
8-310
User Manual
C166S V2
SUBCB
N
*
Bytes
2
2
2
2
4
4
4
V 1.7, 2001-01