![Direct Addressing
Direct addressing:
Code: data store in word form:
Mov ax , [num1]
Mov ax , [num1+2 ]](https://image.slidesharecdn.com/maproject-180415140225/85/Assembly-language-Example-with-mapping-from-C-to-Assembly-9-320.jpg)
![Indirect Addressing
Indirect addressing:
Mov bx , num1
Mov ax , [bx]
Mov ax , [bx+2]](https://image.slidesharecdn.com/maproject-180415140225/85/Assembly-language-Example-with-mapping-from-C-to-Assembly-14-320.jpg)
Assembly language (Example with mapping from C++ to Assembly)
- 2. Assembly language Assembly language Slightly higher-level language Readability of instructions is better than machine language One-to-one correspondence with machine language instructions Assemblers translate assembly to machine code Compilers translate high-level programs to machine code
- 3. Translating Languages English: D is assigned the sum of A times B plus 10. High-Level Language: D = A * B + 10 Intel Assembly Language: mov eax, A mul B add eax, 10 mov D, eax Intel Machine Language: A1 00404000 F7 25 00404004 83 C0 0A A3 00404008 A statement in a high-level language is translated typically into several machine-level instructions
- 4. Flags The FLAGs register is the status register in Intel x86 microprocessors that contains the current state of the processor. Types of flags ? Carry flag Zero flag Parity flag Over flow flag Sign flag
- 5. Registers General registers, Control registers, and Segment registers. The general registers are further divided into the following groups − Data registers, Pointer registers, and Index registers.
- 6. Data Registers AX is the primary accumulator; it is used in input/output and most arithmetic instructions. For example, in multiplication operation, one operand is stored in EAX or AX or AL register according to the size of the operand. BX is known as the base register, as it could be used in indexed addressing. CX is known as the count register, as the ECX, CX registers store the loop count in iterative operations. DX is known as the data register. It is also used in input/output operations. It is also used with AX register along with DX for multiply and divide operations involving large values
- 7. C++ To Assembly Example int num1=5; int num2=6; If (num1>=num2) mov ax, 5 mov bx, 6 cmp ax, bx
- 8. Type of Addressing Direct Addressing Indirect Addressing
- 9. Direct Addressing Direct addressing: Code: data store in word form: Mov ax , [num1] Mov ax , [num1+2 ]
- 10. DIRECT ADDRESSING SIZE MISMATCH ERRORS
- 14. Indirect Addressing Indirect addressing: Mov bx , num1 Mov ax , [bx] Mov ax , [bx+2]
- 18. Jumps Conditional jumps This is performed by a set of jump instructions j<condition> depending upon the condition. Unconditional jumps? This is performed by the JMP instruction. Conditional execution often involves a transfer of control to the address of an instruction that does not follow the currently executing instruction.
- 21. SORTING EXAMPLE