The 8085 microprocessor is an 8-bit microprocessor introduced by Intel in 1976. It is part of the 8080 family of microprocessors and was widely used in various applications during the early days of personal computing and embedded systems. Here are some key features and characteristics of the 8085 microprocessor:
Architecture:
The 8085 microprocessor has a Von Neumann architecture and consists of an 8-bit data bus, 16-bit address bus, and an 8-bit arithmetic logic unit (ALU). It operates at a clock speed of 3 MHz.
Registers:
The 8085 microprocessor has several registers, including:
- Accumulator (A): The primary register used for arithmetic and logical operations.
- General Purpose Registers (B, C, D, E, H, L): These registers can be used for storing data or as operands for various instructions.
- Program Counter (PC): It holds the address of the next instruction to be executed.
- Stack Pointer (SP): It keeps track of the top of the stack for subroutine calls and interrupts.
Instruction Set:
The 8085 microprocessor has a rich instruction set, including data transfer, arithmetic, logical, branch, and I/O instructions. It supports both immediate and direct addressing modes.
Memory:
The 8085 microprocessor can address up to 64 KB of memory. It uses a separate address bus and data bus for accessing memory and I/O devices.
Interrupts:
The 8085 microprocessor supports five interrupt signals: TRAP, RST 7.5, RST 6.5, RST 5.5, and INTR. These interrupts can be used to handle external events and initiate specific routines.
I/O Ports:
The 8085 microprocessor has a limited number of I/O ports, typically two 8-bit ports (Port A and Port B). These ports can be used to interface with external devices.
Operating Voltage:
The 8085 microprocessor typically operates at a 5V power supply.
Assembly Language Programming:
Software development for the 8085 microprocessor is typically done using assembly language. Assembly instructions are mnemonic codes that directly correspond to the machine language instructions executed by the microprocessor.
Despite being an older microprocessor, the 8085 still holds historical significance and is studied as part of computer architecture and microprocessor courses. While it has been largely replaced by more advanced and powerful microprocessors, the fundamental concepts and principles of the 8085 architecture continue to be relevant in modern computing.