©F.M. Rietti Embedded Systems I Controllers Data Sheets

©F.M. Rietti LM-18 Computer Science SSI Embedded Systems I 2 What is a Data Sheet? Datasheet is a document written by controller manufacturer, reporting all major characteristics. Reading Datasheets we are able to decide if controller is good for our scopes Two reading modes: –Electronic Engineer –Systems & Software Engineer Both for Single Chip (MCU) or Single Board

©F.M. Rietti LM-18 Computer Science SSI Embedded Systems I 3 Electronic Eng. Point of view For an Electronic Engineer datasheet is important: –To design circuits schemas around controller –To design PCB layout –To design system case Dirty or clean environment Working temperature range

©F.M. Rietti LM-18 Computer Science SSI Embedded Systems I 4 Sys & SW Eng. Point of View Important data are common for board with a single MCU and some auxiliary chips and complex single board with some peripherals on board, connected from PCB tracks Sys & SW engineers cannot design boardsSys & SW engineer choice a ready made board to build embedded system, adding peripherals and SW Sys & SW engineers cannot design boards (IT law DPR328/2001 designing is for B engineers, we study as C)

©F.M. Rietti LM-18 Computer Science SSI Embedded Systems I 5 Data Sheets Hi Light Temperature (some chips are made in various T ranges) –Standard 0 ÷ +40 (or +70) °C –Extended –40 ÷ +85 °C –Automotive –40 ÷ +110 °C –Storage Price increase with T range

©F.M. Rietti LM-18 Computer Science SSI Embedded Systems I 6 Data Sheets Hi Lights (cont) Packaging –No interest for Sys & SW engineers, but chips with pins and socket can be go out for hi knocks or vibrations, superficial mounting is more robust.

©F.M. Rietti LM-18 Computer Science SSI Embedded Systems I 7 Data Sheets Hi Lights (cont) Supply Voltage (nominal ± range) –Various values from controller market, DC type –Multiple of 1.2V allow battery power supply (Ni-Cd, Ni-Mh, Thionil chlorure, …) Remember in DC mode transformers doesn’t work! –Large availability of DC-DC Integrate Circuits to adapt increasing or decreasing voltage. Remember in DC mode transformers doesn’t work!

©F.M. Rietti LM-18 Computer Science SSI Embedded Systems I 8 Data Sheets Hi Lights (cont) Power Dissipation –Based on package heat transfer limitations not device power consumption Power Supply current –Remember: if controller has outputs, digital or analog, must consider total sum of currents Max Electrical Power = V cc * I ccmax

©F.M. Rietti LM-18 Computer Science SSI Embedded Systems I 9 Data Sheets Hi Lights (cont) Clock –Internal –External (Crystal required) –Range Always remember Fourier series for a square wave: sum of odd harmonics, with amplitude equal V/n.

©F.M. Rietti LM-18 Computer Science SSI Embedded Systems I 10 Data Sheets Hi Lights (cont) Data bits Address bits Memory amount –Program Space –Data Space Interrupts Line(s) Timer(s)

©F.M. Rietti LM-18 Computer Science SSI Embedded Systems I 11 Data Sheets Hi Lights (cont) Interfaces –Digital signals IN (Impedance & Maximum Voltage) –TTL logic –counter OUT (Voltage & Maximum Current ) –TTL logic –PWM

©F.M. Rietti LM-18 Computer Science SSI Embedded Systems I 12 Data Sheets Hi Lights (cont) Interfaces (cont) –Analog signals IN (Impedance, Max. Voltage, current sensing or voltage sensing & resolution bits) OUT (Max. current, Voltage or Current & resolution bits) –Communication (wired) EIA RS232 Ethernet

©F.M. Rietti LM-18 Computer Science SSI Embedded Systems I 13 Data Sheets Hi Lights (cont) Interfaces (cont) –Communication (wired) EIA RS232 Ethernet CAN, LIN, MODBUS, PROFIBUS, … –Communication (radio) Wi-Fi Bluetooth XBee