What is the function of DAA Xchg and AAD instructions in 8086?
POPA − Used to get words from the stack to all registers. XCHG − Used to exchange the data from two locations. XLAT − Used to translate a byte in AL using a table in the memory.
How DAA instruction works in 8086?
The DAA (Decimal Adjust after Addition) instruction allows addition of numbers represented in 8-bit packed BCD code. It is used immediately after normal addition instruction operating on BCD codes. This instruction assumes the AL register as the source and the destination, and hence it requires no operand.
How many types of instructions are there in 8086?
|SUB||Subtract immediate data from accumulator, memory or register.|
|SBB||Subtract immediate data with borrow from accumulator, memory or register.|
|MUL||Unsigned 8-bit or 16-bit multiplication.|
|IMUL||Signed 8-bit or 16-bit multiplication.|
Which register of 8085 is 16 bit?
Stack Pointer: The stack pointer in the 8085 microprocessor is a 16-bit register that stores the address of the top of stack memory.
What is the function of Dad B?
Though it is an arithmetic instruction, by design, flags other than Cy, will not get affected by the execution of this instruction DAD rp. Let us consider DAD B is a sample instruction of this category. As It is 1-Byte instruction so it occupies a single Byte place in the memory.
What is the use of push in 8086?
PUSH then places the operand on the new top of stack, which is pointed to by the stack pointer. The 80386 PUSH eSP instruction pushes the value of eSP as it existed before the instruction. This differs from the 8086, where PUSH SP pushes the new value (decremented by 2).
How is XCHG implemented in an 8086 processor?
On modern CPU’s an xchg is consistently half as fast as a mov and takes twice as many uops, hinting at the temp register being used, this can be done in 2 steps, because the first two assignments are fused into one using register renaming.
How does the xchg instruction exchange two operands?
The XCHG(exchange data) instruction exchanges the contents of two operands. There are three variants: XCHGreg, reg XCHGreg, mem XCHGmem, reg You can exchange data between registers or between registers and memory, but not from memory to memory:
How does the PUSH instruction in XCHG work?
PUSH: – This instruction pushes the register pair onto stack. The contents of the register pair designated in the operand are copied onto the stack in the following sequence. The stack pointer register is decremented and the contents of the highorder register (B, D, H, A) are copied into that location.
What kind of instructions does an 8086 microprocessor do?
The 8086 microprocessor supports 8 types of instructions − Data Transfer Instructions; Arithmetic Instructions; Bit Manipulation Instructions; String Instructions; Program Execution Transfer Instructions (Branch & Loop Instructions) Processor Control Instructions; Iteration Control Instructions; Interrupt Instructions