| REG Code Register Selected | 0 1 1 BL BX | 1 0 0 AH SP | 1 0 1 CH BP | 1 1 0 DH SI |
|---|
What is the function of the 6 byte instruction queue of 8086?
In 8086, a 6-byte instruction queue is presented at the Bus Interface Unit (BIU). It is
used to pre fetch and store at the maximum of 6 bytes of instruction code from the memory
. Due to this, overlapping instruction fetch with instruction implementation increases the processing speed.
Which of the following has a 6 byte long instruction queue?
8086 Queue
is only Six Byte long:
This is because the longest instruction in the instruction set of 8086 is six byte long. Hence with a six byte long queue it is possible to pre-fetch even the longest instruction in the main program.
What are the instructions in 8086?
| OPCODE OPERAND EXPLANATION | IMUL 8 or 16 bit register performs signed multiplication | DIV 8-bit register AX = AX / 8-bit reg. ; AL = quotient ; AH = remainder | DIV 16-bit register DX AX / 16-bit reg. ; AX = quotient ; DX = remainder | IDIV 8 or 16 bit register performs signed division |
|---|
Which instruction of the following is 2 byte instruction?
Two-byte instructions –
Two-byte instruction is the type of instruction in which the first 8 bits indicates the opcode and the next 8 bits indicates the operand. In a two-byte instruction, the
first byte specifies the operation code
and second byte specifies the operand.
How many interrupt 8086 can address?
8086 μP can implement
256 different interrupts
. To store the starting address of a single ISS (Interrupt Service Subroutine), four bytes of memory space are required—two bytes to store the value of CS and two bytes to store the IP value.
What are the features of 8086?
1) The 8086 is a 16-bit microprocessor. The term “16-bit” means that its arithmetic logic unit, internal registers and most of its instructions are designed to work with 16-bit binary words. 2) The 8086 has a
16-bit data bus
, so it can read data from or write data to memory and ports either 16 bits or 8 bits at a time.
Why is 8086 queue only six byte long?
8086 Queue is only Six Byte long:
This is
because the longest instruction in the instruction set of 8086 is six byte long
. Hence with a six byte long queue it is possible to pre-fetch even the longest instruction in the main program.
What is the length of Predecoding instruction byte queue?
Explanation: The length of predecoding instruction byte queue is
6 bytes long
as the maximum size of instruction that supported by 8086 processor is 6 bytes.
How many registers are there in 8086?
The 8086 has
eight more or less general 16
-bit registers (including the stack pointer but excluding the instruction pointer, flag register and segment registers). Four of them, AX, BX, CX, DX, can also be accessed as twice as many 8-bit registers (see figure) while the other four, SI, DI, BP, SP, are 16-bit only.
What are 5 types of instruction operations?
- Data handling and memory operations.
- Arithmetic and logic operations.
- Control flow operations.
- Coprocessor instructions.
- Number of operands.
What is the purpose of SI and DI in 8086?
This
instruction copies the contents of Ax into the memory location whose
address is the sum of the Bx and SI. DI stands for destination index, used as a pointer to the current character being written or compared in a string instruction. It is also available as an offset just like SI.
What is segmented memory 8086?
A segment is a logical unit of memory that
may be up to 64 kilobytes long
. Each segment is made up of contiguous memory locations. … However, it works only with four 64KB segments within the whole 1MB memory. Below is the one way of positioning four 64 kilobyte segments within the 1M byte memory space of an 8086.
Is 3 Byte A instruction?
Three-byte instructions –
Three-byte instruction is the
type of instruction in which the first 8 bits indicates the opcode and the next two bytes specify the 16-bit address
. The low-order address is represented in second byte and the high-order address is represented in the third byte.
What is the length of one Byte instruction?
The length of the one-byte instruction is
This format is
2 byte long
.
Is RAR a 3 Byte instruction?
In 8085 Instruction set, RAR stands for “Rotate Accumulator Right involving Cy flag in rotation”. It is
1-Byte instruction
. … And it is 9-bit rotation of Accumulator and Cy contents.
