The main difference between 8085 and 8086 microprocessor is that 8085 is an 8-bit microprocessor developed by Intel while 8086 is a 16-bit microprocessor, which is an enhanced version of 8085 microprocessor developed by Intel.
8085 and 8086 are two widely used microprocessors developed by Intel. A microprocessor is a device that is used for high processing applications. It operates at a higher clock speed and consists of more memory. It also consists of peripheral interfaces such as USB, UART and high-speed Ethernet. Furthermore, all the IO devices are connected to the CPU. Computers and laptops are two common applications of microprocessors. These applications are capable of performing multiple tasks simultaneously.
Key Areas Covered
1. What is 8085 Microprocessor
– Definition, Functionality
2. What is 8086 Microprocessor
– Definition, Functionality
3. Difference Between 8085 and 8086 Microprocessor
– Comparison of Key Differences
Key Terms
CPU, Databus, Microprocesssor, 8085 Microprocesssor, 8086 Microprocessor, Minimum Mode, Maximum Mode
What is 8085 Microprocessor
8085 Microprocessor is an 8-bit microprocessor. It is a software binary compatible with most Intel 8080 instructions. Also, there are two minor instructions to support interrupts and serial IO features. Moreover, it requires less support circuitry.
Furthermore, this microprocessor requires +5V supply to operate at 3.2 MHz single phase clock. It uses a multiplexed address/data (AD^0 – AD^7) bus. In addition, the 8085 circuit requires an 8-bit address latch. Therefore, Intel manufactured a number of chips with an address latch built in. Moreover, it is in a 40 pin DIP package. It also has an 8-bit data bus, 16-bit address bus, 16-bit program counter, 16-bit stack pointer and six 8 bit registers arranged in pairs.
What is 8086 Microprocessor
8086 Microprocessor is a 16-bit microprocessor chip. The architecture of this processor is x86 architecture. The latest microprocessors of Intel uses this architecture.
The instruction queue can store six instruction bytes from memory. It supports two stages of pipelines called fetch and execute. In the fetch stage, the instructions are fetched from the memory and stored in the instruction queue. The instructions are executed in the execution stage.
Moreover, this microprocessor operates in two modes. They are the minimum mode and maximum mode. The minimum mode is suitable for single processors whereas maximum mode is suitable for multiple processors. 8086 microprocessor consists of 16-bit registers, 16-bit external data bus and internal data bus. Furthermore, this microprocessor has three versions. The operating frequency of regular 8086 is 5MHz; an operating frequency of 8086-2 is 8MHz whereas 8086-1 operating frequency is 10MHz.
Difference Between 8085 and 8086 Microprocessor
Definition
8085 microprocessor is an 8-bit microprocessor produced by Intel and introduced in 1976. But, 8086 microprocessor is a 16-bit microprocessor chip designed by Intel in early 1976.
Type
8085 is an 8-bit microprocessor, while 8086 is a 16-bit microprocessor. Thus, this is the main difference between 8085 and 8086 microprocessor.
Address Bus
Besides, the 8085 microprocessor has a 16-bit address bus, whereas the 8086 microprocessor has 20-bit address bus.
Data bus
Also, 8085 has an 8-bit data bus while 8086 has a16-bit address bus.
Pipelining
Moreover, the 8085 microprocessor does not support pipelining, whereas the 8086 microprocessor supports pipelining. Hence, this is another difference between 8085 and 8086 microprocessor.
Instruction queue
Furthermore, one other difference between 8085 and 8086 microprocessor is that there is no instruction queue in 8085 microprocessor, while there is an instruction queue in 8086.
Memory
An additional difference between 8085 and 8086 microprocessor is that the 8085 microprocessor can access up to 64Kb memory, while 8086 can access up to 1 Mb of memory.
Memory segmentation
Also, 8085 does not support memory segmentation, while 8086 supports memory segmentation.
Frequency
Importantly, the frequency of 8085 microprocessor is 3.2MHz whereas, in 8086 microprocessor, the frequency changes between 5MHz, 8MHz and 10MHz depending on the version.
Multiplication and division
8085 microprocessor does not have multiplication and division instructions, while 8086 has multiplication and division instructions.
Modes
Additionally, 8085 microprocessor has no minimum and maximum modes, while 8086 has minimum and maximum modes.
Cost
Price wise, 8085 microprocessor is less expensive than 8086 microprocessor.
Conclusion
The main difference between 8085 and 8086 microprocessor is that 8085 is an 8-bit microprocessor by Intel while 8086 is a 16-bit microprocessor which is an enhanced version of 8085 microprocessor. Usually, we use these microprocessors to build mobile phones, microwave ovens and washing machines.
References
1.“Intel 8085.” Wikipedia, Wikimedia Foundation, 21 Mar. 2019, Available here.
2.“Intel 8086.” Wikipedia, Wikimedia Foundation, 13 Apr. 2019, Available here.
Image Courtesy:
1.”Intel 8085 microarchitecture” By Appaloosa – Own work (CC BY-SA 3.0) via Commons Wikimedia
2.”Microprocessor 8086 Pin configuration” By Unknown – Dokumentacja mikroprocesora Intel 8086 (Public Domain) via Commons Wikimedia
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