Presentation by adeel
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The execution unit performs logic and arithmetic operations on memory or register data. It receives instructions from the prefetch queue and decodes them, then temporarily stores information in register arrays. The execution unit contains an ALU, general purpose registers including AX, BX, CX and DX, special purpose registers, pointer registers SP and BP, and index registers SI and DI. It performs operations like AND, OR, addition and subtraction on 16-bit data. The flags register stores status flags from the last arithmetic or logical instruction, including carry, auxiliary, parity, zero, sign, and overflow flags.
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Presentation by adeel
- 2. E.U unit performs the following functions. It performs the logic and Arithmetic operation on memory or register. It receives the instruction from pre fetch queue and decodes it. It stores the information temporary in the register array.
- 3. Control Circuit ALU General Purpose Register Special Purpose Register 2 pointer registers 2 index registers
- 6. This is a 16 bit unit which performs the AND, OR, Exclusive, Addition, Subtraction, Increment, Decrement, Complement and Shift functions.
- 8. It has 4 data registers,AX, BX, CX, DX AX, BX, CX and DX registers has 2 8- bit registers to access the high and low byte data registers.The high byte of AX is called AH and the low byte is AL. Similarly,
- 10. Flags Register It is also called status register flags represent result of last arithmetic or logical instruction executed. Conditional flags are as follows: 1. CF (Carry Flag) 2. AF (Auxiliary Flag) 3. PF (Parity Flag) 4. ZF (Zero Flag)
- 11. Flags Register 5. SF (Sign Flag) 6. OF (Overflow Flag) Control register 5. TF (Trap Flag): 6. IF (Interrupt Flag): 7. DF (Direction Flag): And Seven undefined flags register
- 12. 2 pointer registers SP, BP SP (Stack pointer) BP (Base pointer) 2 index registers SI, DI SI(Sours index) DI (Destination index)