8085 Microprocessors Notes

8085 MPU is an 8-bit microprocessor i.e. it can accept, process and provide 8-bit data. It operates on +5V power supply connected at V cc. Power supply ground is connected to Vss. It has 8 data lines (D0 - D7). It has 16 address lines (A0 - A15). It can access 2^16 = 64K of memory. It has 8 bit I/O address. It can access 2^8 = 256 I/O ports. It operates on clock cycle with 50% duty cycle. It operates with a 3MHz clock frequency. The lower 8-bit address bus (A0 - A7) and data bus (D0 - D7) are multiplexed to reduce number of external pins. It has 8-bit accumulator, flag register, instruction register, six 8-bit general purpose registers (B, C, D, E, H and L) and two 16-bit registers (SP and PC). It has five hardware interrupts. They are TRAP, RST 7.5, RST 6.5, RST 5.5 and INTR. It has serial I/O control which allows serial communication. It has control signals (IO/M, RD, WR) to control bus cycles. It has five addressing modes. They are: immediat...