Table of Contents
- 1 What is the size of instruction queue in 8088?
- 2 How many instructions are there in 8088?
- 3 Which has the larger queue the 8088 or 8086?
- 4 What is maximum size of instruction in 8086?
- 5 What is the size of virtual address in 80386 DX?
- 6 How big is the prefetch queue in the 8086?
- 7 What are the side effects of the 8088?
What is the size of instruction queue in 8088?
The 8088 prefetch queue was four bytes deep. The 8086 queue was six bytes deep. Again, these do not correspond to a set number of instructions, but a number of bytes.
How many instructions are there in 8088?
Introduced on June 1, 1979, the 8088 has an eight-bit external data bus instead of the 16-bit bus of the 8086….Intel 8088.
| General information | |
|---|---|
| Instruction set | x86-16 |
| Physical specifications | |
| Transistors | 29,000 |
| Co-processor | Intel 8087 |
What is the size of the instruction queue?
6-bytes
Ans. The instruction queue is 6-bytes in length, operates on FIFO basis, and receives the instruction codes from memory. BIU fetches the instructions meant for the queue ahead of time from memory.
What is the size of instruction queue in 80386?
16-byte
The Prefetch Queue. The 80386 is documented as having a 16-byte prefetch queue. At one time, it did, but due to a bug in the pipelining architecture, Intel had to abandon the 16-byte queue, and only use a 12-byte queue.
Which has the larger queue the 8088 or 8086?
Though the architecture and instruction set of both 8086 and 8088 processors are same, still there are differences between them….Differences between 8086 and 8088 microprocessors.
| S. No. | 8086 microprocessor | 8088 microprocessor |
|---|---|---|
| 8 | It has 6 byte instruction queue. | It has 4 byte instruction queue as it can fetch only 1 byte at a time. |
What is maximum size of instruction in 8086?
64K
The max size is 64K. There is no minimum – you can use only first byte, but the segment is always 64K. Maybe the exception are the last segments – the latest (0xFFFF) is 16 bytes, before the latest are 32, 48, 64 bytes… Generally, 8086 segments are method for addressing of more than 64K with 16 bit address registers.
What is the size of instruction queue in 8085?
The 8085 instruction set is classified into 3 categories by considering the length of the instructions. In 8085, the length is measured in terms of “byte” rather then “word” because 8085 microprocessor has 8-bit data bus. Three types of instruction are: 1-byte instruction, 2-byte instruction, and 3-byte instruction.
Why is the size of an instruction queue in 8086 of 6 bytes?
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 size of virtual address in 80386 DX?
Protected Virtual Address Mode (PVAM) of 80386 Protected mode is used to increase the linear address space up to 4GB and used to execute virtual memory programs of the size of 64TB. Also Protected mode of 80386 is used to run all the existing 8086 and 80286 program with a memory management and protection mechanism.
How big is the prefetch queue in the 8086?
The 8086 architecture has a six-byte prefetch instruction pipeline, while the 8088 has a four-byte prefetch. As the Execution Unit is executing the current instruction, the bus interface unit reads up to six (or four) bytes of opcodes in advance from the memory. The queue lengths were chosen based on simulation studies.
What is the function of instruction queue in 8086?
An instruction queue is used in the 8086 to speed up the average time it takes to process an instruction. Some instructions are faster than the bus, while some are slower. If the CPU had to wait for all of the instructions, there would be gaps of time where the CPU is doing nothing.
What’s the difference between an 8086 and an 8088?
Though the architecture and instruction set of both 8086 and 8088 processors are same, still there are differences between them. The data bus is of 16 bits. The data bus is of 8 bits. It has 3 available clock speeds (5 MHz, 8 MHz (8086-2) and 10 MHz (8086-1)). The memory capacity is 512 kB.
What are the side effects of the 8088?
A side effect of the 8088 design, with the slow bus and the small prefetch queue, is that the speed of code execution can be very dependent on instruction order. When programming the 8088, for CPU efficiency, it is vital to interleave long-running instructions with short ones whenever possible.