Microprocessor system structure

Microprocessor system structure 1/25 Basic components Single-board systems Modular systems

System components 2/25 1. Processor surrounding of processor depends on its type A10 A9 A8 A7 A6 A5 A4 A3 A2 A1 A0 GND RFSH M1 RESET BUSREQ WAIT BUSACK WR RD A11 A12 A13 A14 A15 CLK D4 D3 D5 D6 +5V D2 D7 D0 D1 INT NMI HALT MREQ IORQ Z80 Vcc CPU based on Z80 needs single supply and clock signal: „ready” data, address and control signals U U C1 10p C2 6n8 R1 820 R2 820 X1 2500kHz U CLK BUSACK BUSREQ RESET NMI INT WAIT HALT RFSH WR RD IORQ MREQ M1 D7 D6 D5 D4 D3 D2 D1 D0 A15 A14 A13 A12 A11 A10 A9 A8 A7 A6 A5 A4 A3 A2 A1 A0 U1 Z80ACPU +5V

System components 3/25 CPU based on 8080:

System components 4/25 CPU based on 8085:

System components 5/25 CPU based on 8086 (minimal mode):

System components 6/25 CPU based on 8086 (maximal mode):

System components 7/25 CPU based on 80C51:

System components 8/25 2. Programme memory semiconductor, VLSI, non-volatile; contains at least start-up software; in small system contains all used software. processor DATA ADDR CTRL programme memory (ROM)

System components 9/25 3. Data memory semiconductor, VLSI, volatile; stores data and result of executing programmes; in big systems stores software loaded before execution. processor DATA ADDR CTRL programme memory (ROM) data memory (RAM)

System components 10/25 4. Peripherals I/O ports to data exchange; without them we will not have any advantages of working computer. processor DATA ADDR CTRL programme memory (ROM) data memory (RAM) operator devices commu- nication devices process devices

System components 11/ Operator devices make possible communication between computer and man; I/O ports for keyboard, monitor, display, pointing devices, etc. Basic operator devices: keyboards: alphanumeric or function-numeric; displays: LED or LCD, segmented, mosaic or graphic; printers: by principle of work: needle, laser, ink, thermal; by construction/destination: office, industrial, cash-boxes; monitors: monochromatic i colour, alphanumeric i graphic, CRT i LCD; pointing devices: mouses, touch-pads, scroll-balls, joysticks, touch screens

System components 12/ Communication devices to data exchange between different systems (superior, secondary or equivalent); serial (RS family, CAN, USB, FireWire, InfiniBand, etc.); parallel (Centronics); LAN; modems (radio, optic, cable).

System components 13/ Object devices/process devices I/O ports dedicated to data acquisition and acting on process; analogue I/O; binary I/O; special interfaces (exmp. IEC625).

secondary memories System components 14/25 5. Secondary memories: to store not currently used information; FDD, HDD, CD-ROM, CD-RW, DVD, DVD-RW, etc. processor DATA ADDR CTRL programme memory (ROM) data memory (RAM) operator devices commu- nication devices process devices

secondary memories MM serv. devices System components 15/25 6. Main memory serving devices DMA controllers; DRAM controllers. processor DATA ADDR CTRL programme memory (ROM) data memory (RAM) operator devices commu- nication devices process devices

MM serv. devices secondary memories address decoders System components 16/25 7. Address decoders using address word and control signals activate right memory chip or I/O port processor DATA ADDR CTRL programme memory (ROM) data memory (RAM) operator devices commu- nication devices process devices

address decoders MM serv. devices interrupt controllers secondary memories System components 17/25 8. Interrupt controllers different level of complication, programmable or not; collect individual interrupt signals, queuing them according to priorities, send single interrupt signal to CPU processor DATA ADDR CTRL programme memory (ROM) data memory (RAM) operator devices commu- nication devices process devices

timers RTC address decoders MM serv. devices interrupt controllers secondary memories System components 18/25 9. Timers, Real Time Clocks time delay with chosen precision; clock RTC with calendar. processor DATA ADDR CTRL programme memory (ROM) data memory (RAM) operator devices commu- nication devices process devices

timers RTC address decoders MM serv. devices interrupt controllers secondary memories System components 19/ System bus set of signals needed to information exchange between system components processor programme memory (ROM) data memory (RAM) operator devices commu- nication devices process devices DATA ADDR CTRL

System structure 20/25 MICROPROCESSOR SYSTEM STRUCTURE SINGLE-BOARD MODULAR

Single-board microcomputer 21/25 timers RTC address decoders MM serv. devices interrupt controllers secondary memories processor DATA ADDR CTRL program memory (ROM) data memory (RAM) opera- tor devices commu- nication devices process devices operator console communication interfaces acting devices measuring devices, etc.

Single-board microcomputer 22/25 Features: all necessary system components (CPU, MM, I/O ports, interrupt circuits, timers, etc.) placed on the same printed board; system dedicated to specified tasks (local controllers, etc.); to embed in other devices; difficult service - replacing whole system-board; Designed as: „just for needs”, minimal cost - so called “closed system”; universal (allowing extension, modification) - so called “open system”

In modern systems usually one module Modular system 23/25 Construction: comm. devices operator devices second. mem. ROM RAM PP inter- rupts addr dec. RTC process devices DADA DADA

Modular system 24/25 Features: few modules with defined functions, which allow to construct different hardware according to needs; defined parallel system bus, connecting all modules; specific mechanical construction; easy extended and modified; easy designing new applications using the set (“library”) of standard modules; Modular systems dominate in field of industrial applications

Modular system 25/25