Assembly Programming For All Platforms, Learn To Code

Memory segmentation is the division of a computer's primary memory into segments or sections. In a computer system using segmentation, a reference to a memory location includes a value that identifies a segment and an offset (memory location) within that segment.

A processor register (CPU register) is one of a small set of data holding places that are part of the computer processor. A register may hold an instruction, a storage address, or any kind of data (such as a bit sequence or individual characters). Some instructions specify registers as part of the instruction.

A memory buffer register (MBR), commonly referred to as a memory data register (MDR) is the register in a computer's processor, or central processing unit, CPU, that stores the data being transferred to and from the immediate access storage. It contains the copy of designated memory locations specified by the memory address register. It acts as a buffer allowing the processor and memory units to act independently without being affected by minor differences in operation. A data item will be copied to the MBR ready for use at the next clock cycle, when it can be either used by the processor for reading or writing or stored in main memory after being written.

In computer processor architecture, a pointer register is a register that is used to store a memory address. You may be able to use it for other purposes too, but generally, there are instructions that interpret it as a memory address, and fetch the data located at that address.

An index register in a computer's CPU is a processor register used for modifying operand addresses during the run of a program, typically for doing vector/array operations. The contents of an index register is added to an immediate address to form the "effective" address of the actual data.

A control register is a processor register which changes or controls the general behaviour of a CPU or other digital device. Common tasks performed by control registers include interrupt control, switching the addressing mode, paging control, and coprocessor control.

Segment Registers. Segments are specific areas defined in a program for containing data, code and stack. There are three main segments − CodeSegment − It contains all the instructions to be executed. A 16-bit Code Segment register or CS register stores the starting address of the code segment.

Register Addressing. In this addressing mode, a register contains the operand. Depending upon the instruction, the register may be the first operand, the second operand or both. As processing data between registers does not involve memory, it provides fastest processing of data.

Immediate Addressing. An immediate operand has a constant value or an expression. When an instruction with two operands uses immediate addressing, the first operand may be a register or memory location, and the second operand is an immediate constant.

Direct Addressing Mode. Direct addressing mode means that the value for a given instruction in assembly programming is pointed to by a given value. This means the value is variable, based on what is stored in memory at a given address.

Register direct addressing is the simplest addressing mode in which the source or destination of an operand is a data register or an address register. ... In immediate addressing the actual operand forms part of the instruction.

Indirect Addressing. Indirect addressing is a scheme in which the address specifies which memory word or register contains not the operand but the address of the operand.

MOV instruction is a copy instruction. MOV copies the source operand to the destination operand without affecting the source.

Learn about allocating storage space for initialised data

Learn about allocating storage space for uninitialised data

Learn how to create multiple variables in your Assembly application

Declaring multiple variables in a single declaration can cause confusion regarding the types of the variables and their initial values. If more than one variable is declared in a declaration, care must be taken that the type and initialised value of the variable are handled correctly.

The EQU directive gives a symbolic name to a numeric constant, a register-relative value or a PC-relative value.

Numeric constants are 32-bit integers. You can set them using unsigned numbers in the range 0 to 2^32-1, or signed numbers in the range -2^31 to 2^31 -1. However, the assembler makes no distinction between -n and 2^32-n.

In programming, a constant is a value that never changes. The other type of values that programs use is variables, symbols that can represent different values throughout the course of a program. A constant can be. a number, like 25 or 3.6. a character, like a or $

Increment and decrement operators are unary operators that add or subtract one, to or from their operand, respectively. They are commonly implemented in imperative programming languages. C-like languages feature two versions (pre- and post-) of each operator with slightly different semantics.

Increment and decrement operators are unary operators that add or subtract one, to or from their operand, respectively. They are commonly implemented in imperative programming languages. C-like languages feature two versions (pre- and post-) of each operator with slightly different semantics.

The ADD instruction adds a source operand to a destination operand.

The SUB instruction subtracts a source operand from a destination operand.

A mathematical operation performed on a pair of numbers in order to derive a third number called a product. For positive integers, multiplication consists of adding a number (the multiplicand) to itself a specified number of times. Thus multiplying 6 by 3 means adding 6 to itself three times.

Division is splitting into equal parts or groups. It is the result of "fair sharing". Example: there are 12 chocolates, and 3 friends want to share them, how do they divide the chocolates? Answer: They should get 4 each.

The AND instruction is used for supporting logical expressions by performing bitwise AND operation. The bitwise AND operation returns 1, if the matching bits from both the operands are 1, otherwise it returns 0.

The OR instruction is used for supporting logical expression by performing bitwise OR operation. The bitwise OR operator returns 1, if the matching bits from either or both operands are one. It returns 0, if both the bits are zero.

Performs a bitwise exclusive OR (XOR) operation on the destination (first) and source (second) operands and stores the result in the destination operand location. The source operand can be an immediate, a register, or a memory location; the destination operand can be a register or a memory location. (However, two memory operands cannot be used in one instruction.) Each bit of the result is 1 if the corresponding bits of the operands are different; each bit is 0 if the corresponding bits are the same.

The binary NOT operation has one input and one output. It is like the NEGATIVE operation which takes one argument (one input) and produces one result (one output).

The input to a binary NOT operation can only be 0 or 1 and the result can only be 0 or 1

The binary NOT operation (also known as the binary NOT function or complement function or bit invert function) will always produce a 1 output if its input is 0 and will produce a 0 output if its input is 1.

Compare (cmp) Instruction. The compare (cmp) instruction compares two numeric values. ... Additionally, if the instruction is a signalling comparison form and one or more of the source operands is a quiet NaN, then an invalid operation exception must be generated.

Conditional means it may not be followed depending on some condition.Unconditional means that is program flow reaches that point it always will continue at the target. A if and a switch are a conditional jumps.

Conditional Jump. If some specified condition is satisfied in conditional jump, the control flow is transferred to a target instruction. There are numerous conditional jump instructions depending upon the condition and data.

ASCII (American Standard Code for Information Interchange) is the most common format for text files in computers and on the Internet. In an ASCII file, each alphabetic, numeric, or special character is represented with a 7-bit binary number (a string of seven 0s or 1s). 128 possible characters are defined.

In programming, a named section of a program that performs a specific task. In this sense, a function is a type of procedure or routine. Some programming languages make a distinction between a function, which returns a value, and a procedure, which performs some operation but does not return a value.

Basic features of Stack. Stack is an ordered list of similar data type. Stack is a LIFO (Last in First out) structure or we can say FILO (First in Last out). push() function is used to insert new elements into the Stack and pop() function is used to remove an element from the stack.

Printing numbers is very difficult in Assembly, let's create a function to handle printing numbers.

Recursion in computer science is a method of solving a problem where the solution depends on solutions to smaller instances of the same problem. The approach can be applied to many types of problems, and recursion is one of the central ideas of computer science.