Microprocessor archetecture
- 1. Ms. Ruchi Srivastava JETGI 1
- 2. Ms. Ruchi Srivastava JETGI 2
- 3. • A microprocessor is a multipurpose, programmable, clock – driven, register based electronic device. • It consists of four basic parts: • Processor • Memory • Input • Output Ms. Ruchi Srivastava JETGI 3
- 4. Ms. Ruchi Srivastava JETGI 4
- 5. Ms. Ruchi Srivastava JETGI 5
- 6. Ms. Ruchi Srivastava JETGI 6
- 7. • Address Bus • Data Bus • Control Bus Ms. Ruchi Srivastava JETGI 7
- 8. • Machine Language • Assembly Language • High Level Languages Ms. Ruchi Srivastava JETGI 8
- 9. An 8 – bit processor Having A 16 – bit Address Bus Ms. Ruchi Srivastava JETGI 9
- 10. ARCHITECTURE OPERATIONS • ALU • Register Array • Control Unit • System Bus • Opcode Fetch • Memory Read • Memory Write • Input Read • Output Read Ms. Ruchi Srivastava JETGI 10
- 11. Accumulator Flag Register B C D E H L Stack Pointer (SP) Program Counter (PC) Ms. Ruchi Srivastava JETGI 11
- 12. X1 1 40 VCC X2 2 39 HOLD RESET OUT 3 38 HLDA SOD 4 37 CLK (OUT) SID 5 36 TRAP 6 35 READY RST 7.5 7 34 IO/ RST 6.5 8 33 S1 RST 5.5 9 32 INTR 10 31 11 30 ALE AD0 12 29 S0 AD1 13 28 A15 AD2 14 27 A14 AD3 15 26 A13 AD4 16 25 A12 AD5 17 24 A11 AD6 18 23 A10 AD7 19 22 A9 VSS 20 21 A8 Ms. Ruchi Srivastava JETGI 12
- 13. • Intel 8085 is a 40 – pin IC. • The various signals on these pins can be classified into six groups: o Address Bus o Data Bus o Control and Status signals o Externally Initiated signals o Serial I/O ports o Power Supply and Frequency signals Ms. Ruchi Srivastava JETGI 13
- 14. Pin No. 40 – VCC Pin No. 20 – VSS Pin No. 01 – X1 Pin No. 02 – X2 Pin No. 37 – CLK (OUT) Ms. Ruchi Srivastava JETGI 14
- 15. • VCC & VSS are the power supply pins. • X1 and X2 are the crystal clocks. Each having a frequency of 6 MHz. The frequency is internally divided by two. So the system works at a frequency of 3 MHZ. • CLK (OUT) is Clock Out. It is used to give system clock to other devices. Ms. Ruchi Srivastava JETGI 15
- 16. Pin No. (12 – 19) – AD0 – AD7 Pin No. (21 – 28) – A8 – A15 AD0 – AD7 – Multiplexed Address/Data Bus Pin no. 12 – 19 are the multiplexed pins. They serve the purpose of address bus as well as data bus. As address bus, they serve as, lower order address bus. A8 – A15 – Address Bus Pin no. 21 – 28, serve as, higher order address bus. Ms. Ruchi Srivastava JETGI 16
- 17. Pin No. 29 & 33 – S0 & S1 Pin No. 30 – ALE Pin No. 31 - Pin No. 30 - Pin No. 30 – IO/ WR RD M Ms. Ruchi Srivastava JETGI 17
- 18. S0 & S1 – are the status signals. to identify various microprocessor operations. ALE – Address Latch Enable It is a control signal. It is used to demultiplex the address/data bus. It is a control signal to initiate the write operation. WR Ms. Ruchi Srivastava JETGI 18
- 19. - It is a control signal to initiate the operation. IO/ - It is a control signal to activate memory/IO buffer. RD M Ms. Ruchi Srivastava JETGI 19
- 20. Pin No. 3 – RESET OUT Pin No. 6 - TRAP Pin No. 7 – RST 7.5 Pin No. 8 – RST 6.5 Pin No. 9 – RST 5.5 Pin No. 10 - INTR Pin No. 11 - Pin No. 35 - READY Pin No. 36 - Pin No. 38 - HLDA Pin No. 39 - HOLD INTA RESETIN Ms. Ruchi Srivastava JETGI 20
- 21. TRAP, RST 7.5, RST 6.5, RST5.5 & INTR Are five interrupts on 8085 chip, with TRAP having highest priority, and INTR having lowest priority Except INTR, all the other four interrupts are vectored. Only INTR is non-vectored interrupt. - is interrupt acknowledgement. This signal is initiated by the processor, to respond to an interrupting device. INTA Ms. Ruchi Srivastava JETGI 21
- 22. HOLD – This signal is used by a peripheral to request the processor to gain control over the system bus. HLDA – This signal is initiated by the microprocessor, in response to HOLD signal. READY – Signal on this pin is sent by a slow responding peripheral, in order to delay the microprocessor Ms. Ruchi Srivastava JETGI 22
- 23. - When the signal on this pin goes low, the processor is reset. RESET OUT – This signal s used to reset other devices, when microprocessor is being reset. RESETIN Ms. Ruchi Srivastava JETGI 23
- 24. Pin No. 4 – SOD Pin No. 5 – SID There are only two pins under this category – SID – Serial Input Data SOD – Serial Output Data These pins are used for serial input/output data transmission. Ms. Ruchi Srivastava JETGI 24