Features Of 8085 Microprocessor

It is an 8-bit microprocessor designed by intel in 1977 .8085 is pronounced as an “eighty-eighty-five” microprocessor. The features of the 8085 microprocessor are given below:

1. It is an 8-bit microprocessor that can accept, process or provides 8-bit data simultaneously.
2. The intel 8085 uses a single +5v power supply connected at Vcc; the power supply ground is connected to Vss.
3. It has 8 data lines and 16-bit address lines hence capacity is 216=64 KB of memory.
4. It is a single chip NMOS device using 6200 transistors.
5. It provides five hardware interrupts: TRAP, RST 5.5, RST 6.5, RST 7.5 and INTR. and 8 software interrupts.
6. It has 80 basic instructions and 246 opcodes.
7. It has 8-bit I/O Addresses, hence it can address 2^8=256 inputs ports and 256 output ports.
8. It is available in 40 pins dual inline (DIP) package.
9. 8085 microprocessor provides one accumulator, one flag register, 6 general-purpose registers (B, C, D, E, H, and L) and two special-purpose registers (program counter and stack pointer).
10. 8085 microprocessor has the capability to share its bus with an external bus controller (Direct Memory Access controller; for transferring large amounts of data from memory to I/O and vice-versa.
11. 8085 microprocessor provides two serial input and output lines which are SOD and SID; it means serial peripherals can interfere with 8085 microprocessor directly.
12. It has multiplexed Addresses and data bus(ADo-AD7).
13. It has a mechanism by which it is possible to increase its interrupt handling.
14. The external hardware (another microprocessor or equivalent master) can detect which machine cycle microprocessor is executing using status signals (IO/M, S₀, S₁) This This feature is very useful when more than one processors are using common system resources (memory and I/O devices).
15. It provides control signals (IO/M, RD, WR) to control the bus cycles and hence external bus controller isn’t required.
16. It can be used to implement a three-chip microcomputer with supporting I/O devices like IC 8155 and IC 8355.
17. It supports 74 instructions with following addressing modes: Immediate, Register, Direct, Indirect, Implied.
18. It operates on a clock cycle with a 50% duty cycle.
19. It can operate with a 3 MHz clock frequency . The 8085A-2 version can operate at a maximum frequency of 5MHz.
20. It has on cheap clock generator.