Differences between 8085 and 8086 microprocessor
In the changing world of technologies, the devices used are also changing. Let us take a look at the changes between 8085 series of microprocessors and 8086 series of microprocessors.
Serial No. | 8085 microprocessor | 8086 microprocessor |
---|---|---|
1 | The data bus is of 8 bits. | The data bus is of 16 bits. |
2 | The address bus is of 16 bits. | The address bus is of 20 bits. |
3 | The memory capacity is 64 KB. Also 8085 Can Perform Operation Up to 28 i.e. 256 numbers. A number greater than this is to taken multiple times in 8 bit data bus. | The memory capacity is 1 MB. Also 8086 Can Perform Operation up to 216 i.e. 65,536 numbers. |
4 | The input/output port addresses are of 8 bits. | The input/output port addresses are of 8 bits. |
5 | The operating frequency is 3.2 MHz. | The operating frequency is 5 MHz, 8MHZ,10MHZ. |
6 | 8085 MP has Single Mode Of Operation. | 8086 MP has Two Modes Of Operation. 1. Minimum Mode = Single CPU PROCESSOR 2. Maximum Mode = Multiple CPU PROCESSOR. |
7 | It not have multiplication and division instructions. | It have multiplication and division instructions. |
8 | It does not support pipe-lining. | It supports pipe-lining as it has two independent units Execution Unit (EU) and Bus Interface Unit (BIU). |
9 | It does not support instruction queue. | It supports instruction queue. |
10 | Memory space is not segmented. | Memory space is segmented. |
11 | It consists of 5 flags(Sign Flag, Zero Flag, Auxiliary Carry Flag, Parity Flag, Carry Flag). | It consists of 9 flags(Overflow Flag, Direction Flag, Interrupt Flag, Trap Flag, Sign Flag, Zero Flag, Auxiliary Carry Flag, Parity Flag, Carry Flag). |
12 | It is low cost Microprocessor | It is comparatively High cost Microprocessor. |
13 | There are 5 Addressing Modes. | There are 11 addressing modes. |
14 | There is no concurrency in Fetching, Decoding and execution. | There is Concurrency in Fetching , Decoding and Execution because of instruction queue. |
15 | It has almost 6500 transistors. | It has almost 29000 transistors. |
16 | It is Accumulator based Microprocessor because Accumulator contains major activity in ALU Operations in store and updating calculations. | It is General Purpose Registers(GPR) based microprocessor because there is not specific Accumulator attached with the input of ALU. all GPR’s are connected with it via Bus. |
17 | Integer ,Decimal and Hexadecimal arithmetic is supported | It also supports ASCII Arithmetic over Integer, Decimal and Hexadecimal. |
18 | It needed less external hardware. | It needed more external hardware. Because here more than 1 processor works and additional external processor can also be employed as per requirements. |
19 | It runs over 50% duty cycle. That means for one instruction cycle clock pulse held high for 50% of the pulse. | It runs over 33% duty cycle. That means for one instruction cycle clock pulse held high for 33% of the pulse. |
20 | In 8085 Microprocessor for immediate addressing modes there is instructions containing “I” in it. e.g. MVI , LXI etc. | In 8086 Microprocessor for immediate addressing modes there is no instruction containing “I” in it. In other words there is no MVI instruction in 8086 for moving/transfer data. Only MOV instruction is sufficient. |
21 | In 8085 microprocessor ADD ,SUB instructions were carried out in Accumulator by default. It is used only 1 register for arithmetic operation because another register is fixed and it is accumulator. Example : ADD C will do [A]<- [A] + [C] | In 8086 microprocessor , we can give source and destination register and according to that addition or any arithmetic operations will be performed. For Example : ADD AX,BX will do [AX] <- [AX] + [BX] |