Data manipulation instructions have computational capabilities. They perform arithmetic, logic, and shift operations on data.There are three types of data manipulation instructions are as follows −Arithmetic InstructionsArithmetic operations include addition, subtraction, multiplication, and division. Some computers provide instructions only for addition and subtraction operations and generate multiplication and division operations from these two operations. Each instruction is represented by a mnemonic symbol.The table shows some of the arithmetic instructions and their respective mnemonic symbols.Arithmetic InstructionsNameMnemonic SymbolsLoadLDStoreSTMoveMOVExchangeXCHInputInOutputOUTPushPUSHPopPOPThe description of these instructions is as follows −Increment − The increment instruction adds 1 to the value stored in the register or memory word.Decrement ... Read More

Data transfer instructions transfer the data between memory and processor registers, processor registers, and I/O devices, and from one processor register to another. There are eight commonly used data transfer instructions. Each instruction is represented by a mnemonic symbol.The table shows the eight data transfer instructions and their respective mnemonic symbols.Data Transfer InstructionsNameMnemonic SymbolsLoadLDStoreSTMoveMOVExchangeXCHInputInOutputOUTPushPUSHPopPOPThe instructions can be described as follows −Load − The load instruction is used to transfer data from the memory to a processor register, which is usually an accumulator.Store − The store instruction transfers data from processor registers to memory.Move − The move instruction transfers data from ... Read More

The operands of the instructions can be located either in the main memory or in the CPU registers. If the operand is placed in the main memory, then the instruction provides the location address in the operand field. Many methods are followed to specify the operand address. The different methods/modes for specifying the operand address in the instructions are known as addressing modes.Types of Addressing ModesThere are various types of Addressing Modes which are as follows −Implied Mode − In this mode, the operands are specified implicitly in the definition of the instruction. For example, the instruction "complement accumulator" is ... Read More

Instructions in a computer can be of multiple lengths with a variable number of addresses. The various address fields in the instruction format of a computer vary as per the organization of its registers. It depends on the multiple address fields the instruction can be categorized as three address instructions, two address instructions, one address instruction, and zero address instruction.Three Address InstructionsThe general format of a three address instruction is defined as −operation source 1, source 2, destinationADD A, B, Cwhere A, B, and C are the three variables that are authorized to a different area in the memory. ‘ADD’ ... Read More

Instruction includes a set of operation codes and operands that manage with the operation codes. Instruction format supports the design of bits in an instruction. It contains fields including opcode, operands, and addressing mode.The instruction length is generally preserved in multiples of the character length, which is 8 bits. When the instruction length is permanent, several bits are assigned to opcode, operands, and addressing modes.The function of allocating bits in the instruction can be interpreted by considering the following elements −Number of addressing modesNumber of operandsNumber of CPU registersNumber of register setsNumber of address linesThe figure displayed the general IA-32 ... Read More

A stack can be executed in the CPU by analyzing an area of the computer memory to a stack operation and utilizing a processor register as a stack pointer. In this method, it is performed in a random access memory connected to the CPU.An area of the computer memory is broken into three segments such as program, data, and stack. The address of the next instruction in the program is saved in the pointer Program Counter (PC). The Address Register (AR) points to an array of the information. SP continually influences the address of the element present at the top ... Read More

Stack is also known as the Last In First Out (LIFO) list. It is the most important feature in the CPU. It saves data such that the element stored last is retrieved first. A stack is a memory unit with an address register. This register influence the address for the stack, which is known as Stack Pointer (SP). The stack pointer continually influences the address of the element that is located at the top of the stack.It can insert an element into or delete an element from the stack. The insertion operation is known as push operation and the deletion ... Read More

A set of flip-flops forms a register. A register is a unique high-speed storage area in the CPU. They include combinational circuits that implement data processing. The information is always defined in a register before processing. The registers speed up the implementation of programs.Registers implement two important functions in the CPU operation are as follows −It can support a temporary storage location for data. This supports the directly implementing programs to have fast access to the data if required.It can save the status of the CPU and data about the directly implementing program.Example − Address of the next program instruction, ... Read More

The microinstructions can be determined by symbols. It is interpreted to its binary format with an assembler. The symbols should be represented for each field in the microinstruction. The users should be enabled to represent their symbolic addresses. Each line in an assembly language represents symbolic instruction. These instructions are divided into five fields such as label, micro-operations, CD, BR, and AD.The fields that specify the following information are as follows −The label field may be empty or it may specify a symbolic address. A label is terminated with a colon (:).The micro-operations field consists of one, two, or three ... Read More

A microinstruction format includes 20 bits in total. They are divided into four elements as displayed in the figure.F1, F2, F3 are the micro-operation fields. They determine micro-operations for the computer.CD is the condition for branching. They choose the status bit conditions.BR is the branch field. It determines the type of branch.AD is the address field. It includes the address field whose length is 7 bits.The micro-operations are divided into three fields of three bits each. These three bits can define seven different micro-operations. In total there are 21 operations as displayed in the table.Symbols with their Binary Code for ... Read More