chapter 5

ARITH METIC INSTRUCTIONS

ARITH METIC INSTRUCTIONS

addition, subtraction, multiplication, division, comparison

AND

-NOT

TEST

-OR

-Shift

XOR

-Rotate

LOGIC INSTRUCTIONS

ADDITION

appears in many form of microprocessor

ADC INSTRUCTION

second form of addition

INCREMENT INSTRUCTION

is a special type of addition that adds 1 to a number

SEGMENT REGISTERS

can only be pushed moved, or popped.

REGISTER ADDITION

Whenever arithmetic and logic instruction. execute, the contents of the flag register change

IMMEDIATE ADDITION

is emplyod known whenever data are constant or added.

meMORY-TO-REGISTER ADDITION

requires data to be added to the AL register

ARRAY ADDITION

are sequential lists of data

INCREMENT ADDITION

Instructions aad 1 to any register. or memory location, except a segment register

ADDITION-WITH-CARRY

adds the bit in the carry Flag to the operand data.

ADDITION-WITH-CARRY

mainly appears in software that adds numbers that are wider than 16 bits

EXCHANGE AND ADD

appears in the 80486 instruction set and continues through the 8-core 2

EXCHANGE AND ADD

adds the source the destination and stores the sum in the destination.

SUBTRACTION (SUB)

Forms use any addresing mode 8, 16, 32

DECREMENT (DEC)

subtracts 1 From any registers or memory locations.

subTRACT WITH BORROW (SBB)

numbers that are wider than to 16 bits. 32 bits must occasionally be subtracted

subTRACT WITH BORROW (SBB)

Functions as a regular subtraction, except or 32 the carry)

REGISTER SUBTRACION

After modifies each subtraction, the microprocessor the contents of the Flag register

COMPARISON (CMP)

is a subtraction that changes the only Flag bits the destination operand never change

COMPARISON (CMP)

useful for checking the entire contents of a register or a memory location against another value

COMPARISON (CMP)

- is normally followed by a conditional jump instruction.

COMPARE and EXCHANGE CCMPX CH6)

compares the destination operand with the accumalator

COMPARE and EXCHANGE CCMPX CH6)

If they are equal, the source operand is copied into the destination.

PENTIUM-CORE 2

contain special circuitry that performs a multiplication in as little as one docking period

MULTIPLICATION

is performed on bytes, words, or and can be signed integer double words or unsigned integer.

8-BIT MULTIPLICATIOM

if the most significant 8 bits of the results are zero, both cand o Flag bits equal to zero

DIVIDEND

aways a double-width divided that is divided by the operand.

diVIDE OVERFLOW

occurs when a small number divides into a larger number

REMAINDER

could be used to round the quotient or just dropped to truncate the quotient.

DECIMAL ADJUST AFTER ADDITION CDAA)

DECIMAL ADJUST AFTER SUBTRACHON (DAS)

TWO INSTRUCTIONS CORRECT THE RESULTE OF BCD

DAA INSTRUCTION

Follows the ADD or ADC instruction to adjust the result in to a BCD result

aaa

aad

aam

aas

4 Instruction USED with Asll arithmetic

AAA INSTRUCTION

The addition of two bene-digit Asll coded number will not result in any useful data

AAD

appears before a division

AAM

Follows the multiplication instruction after multiplying two one-digit unpacked BCD numbers

aND INSTRUCTION

performs logical multiplication

MASKING

the task of clearing a bit in a binary number.

OR

performs logical addition culled the an is often Inclusive Or Function

TEST INSTRUCTION

-perfoms the AND operation.

TEST INSTRUCTION

only affects the condition of the Flag register, which indicates the resut of the test

NOT

-inverts all bits of double word a byte, word,

NEG

two is complements a number, which means that signed the number arithmetic sign of a changes

SHIFT

position or move numbers to the left or right within a register or memory location

ROTATE

position binary data by rotating the information in a register or memory location

ROTATE

often used to shift or position numbers that are wider the 16 bits

BIT SCAN

don't shift they do or rotate number, scan through a number searching for 1 bit