03_Handout_1(26) (1).pdf

IT2102 Embedded System Structure Input Block (Marwedel, 2017 & Pan, 2018) The input block accepts the data signals from the external world into the system which may be directed to any number of destinations. A sensor is a device that measures a physical quantity. It can be designed for virtually e...

IT2102 Embedded System Structure Input Block (Marwedel, 2017 & Pan, 2018) The input block accepts the data signals from the external world into the system which may be directed to any number of destinations. A sensor is a device that measures a physical quantity. It can be designed for virtually every physical quantity. ▪ Light Sensitive Sensor - an electromagnetic radiation detector that uses ultraviolet to far infrared spectral range. Electric signals can be detected as an input when photons are absorbed by the material. o Photodiode is a reverse-biased semiconducting optical sensor that is biased against its easy flow direction so that the current is very low. Temperature Sensor - provides temperature feedback to a system controller to make decisions. Line-tracking Sensor - can detect white lines in black and black lines in white via the TTL signal. Ultrasonic Sensor - uses sonar to determine the distance from an object. The sensor is a non-contact distance measurement equipment that uses a timing variable, measured from the transmission signal till a reflected signal is received from the object. Motion Sensor - is an electronic device that is used for motion detection. It contains an electronic sensor that quantifies motion and can either be integrated with or connected to other devices that alert a user of the presence of a moving object that is within the field of view of the sensor. Gas Sensors - are wieldy used to detect gas leakages of LPG, Butane, Propane, Methane, Alcohol, Hydrogen, and smoke in houses and factories. It is composed of a micro AL2O3 ceramic tube, tin dioxide sensitive layer, electrode, and heater measurer fixed into a sensitive component. Hall Sensor - is an omni-polar magnet sensor used to detect magnetic objects. It can be used for proximity switching, positioning, speed detection, and current sensing applications. Color Sensor - is a complete color detector that can detect and measure a nearly limitless range of visible colors. The applications include test strip reading, sorting color, ambient light sensing/calibration, etc. Digital Tilt Sensor - is a digital tilt switch in which there are two modules: mercury-based and ball-based. Triple Axis Accelerometer - is an analog voltage output sensor that detects the acceleration of a moving object. It can be used for detecting acceleration information or measuring the slope angle for your devices. Analog Sound Sensor - is used in detecting loud sounds in an ambient environment. It uses an electret condenser microphone to convert sound energy into an electrical signal, just like how a speaker operates. Voice recognition - is a technology through which sounds, words, or phrases spoken by humans are converted into electrical signals. These signals are transformed into coding patterns that have been assigned meaning. Vibration Sensor - is a digital plug that plays sensor blocks. It is made up of a spring and a conductive material passing through the center of the spring. Flame Sensor - can be used to detect fire or other wavelengths at 760-1100 nm light. The detection angle is roughly 60° and the sensor is particularly sensitive to the flame spectrum. Capacitive Touch Sensor - When any object with capacitive characteristics comes close to a capacitive touch sensor, it acts as another capacitor due to its dielectric nature. Image sensors o CMOS sensor - The architecture of CMOS sensor arrays is similar to that of standard memories in which individual pixels can be randomly addressed and read out. o Charge-coupled Devices (CCDs) - In CCD technology, charges must be transferred from one pixel to the next until they can finally be read out at an array boundary. Joystick Module - simply connects to two analog outputs based on the commands: X and Y control. It is made up of two potentiometers and a press button which provides a solution to move robots to a target directly. Biometric sensors - Methods for biometric authentication include iris scans, fingerprint sensors, and face recognition. Radio-frequency identification (RFID) - This technology is based on the response of a tag to radio frequency signals. o The tag consists of an integrated circuit and an antenna which provides identity to an RFID reader. 03 Handout 1 *Property of STI  [email protected] Page 1 of 3  IT2102 Datapath Block and Control Block Information must be communicated before it can be processed in an embedded system. The datapath and control block coordinates the activities of the system as well as performing the computations and data manipulation operations necessary to execute the application. Datapath Communication (Marwedel, 2017) o Channels are abstract entities characterized by the essential properties of communication, such as maximum information transfer capacity and noise parameters. o Communication media are the physical entities enabling communication. The probability of communication errors can be computed using communication theory techniques. ▪ Wireless media (RF, infrared), optical media (fibers), and wires. Control Block - Processing Units (Allaboutcircuits.com & Marwedel, 2017) o Package Type ▪ System-in-Package (SiP) - This module is a single component that embeds in a package all necessary components of an electronic sub-system such as processors, power module ICs, RAM, passive components, and crystal oscillators. This module is soldered on top of the motherboard. ▪ Package-on-a-Package (PoP) - It stacks single-component packages vertically, connected via ball grid arrays. Packages can be discrete components (memory, CPU, other logic) or a System-in-a-Package stacked with another package for added or expanded functionality. ▪ System-on-a-Chip (SoC) - It brings together all the necessary components of a computer into a single chip or integrated circuit. It can be based on either a microcontroller or a microprocessor. Example: Rasp Pi. o Processor Type ▪ Very Long Instruction Word (VLIW) Processors - Several operations or instructions are encoded in a long instruction word (called instruction packet) and are assumed to be executed in parallel. Explicit Parallelism Instruction Set Computer (EPIC) - uses instructions that explicitly identify operations to be performed in parallel. ▪ Multicore Processors - These processors integrated on the same chip are called multicores. The integration of multiple cores on the same die enables much faster communication. Homogeneous multicore architecture - Advantages of homogeneous multi-core architectures include the design effort is limited and the software can be migrated from one processor to another one. Heterogeneous multicore architecture - This is best suited for certain applications or run-time scenarios. This architecture must be used to achieve the best energy efficiency that is feasible. ▪ Graphics Processing Units (GPU) - Current GPUs try to run a large number of computations concurrently in order to achieve the desired performance. The goal is to keep many processing units busy. ▪ Multiprocessor Systems-on-a-Chip (MPSoCs) - These are heterogeneous multi-core systems that have been merged with GPUs. The architecture does not only contain processor cores but it comprises a number of additional system components, such as memory management units and interfaces for peripheral devices. The whole system is integrated on one chip. 03 Handout 1 *Property of STI  [email protected] Page 2 of 3  IT2102 Memory Block (Pan, 2018 & Delkin Industrial, 2021) The role of memory blocks is to move and read instructions generated by the CPU. This can lead to operations being performed that cause data to be written back to memory. The memory block serves to hold collections of program instructions, as well as to provide short-term storage for input data, output data, and intermediate results of computations. Types o ROM - Read-Only Memory (Embedded instructions and flash-programmable) o RAM - Random Access Memory (Volatile) ▪ Processor registers ▪ Working memory (Main Memory Ram) ▪ Buffer memory (Caches, Buffers, and scratchpad memory) Compression Techniques o Predicated Execution - This is a method of execution wherein an instruction is executed if and only if a certain condition concerning values in the condition code registers is met. o Dictionaries - Each instruction pattern is stored only once. For each value of the program counter, a lookup table provides a pointer to the corresponding instruction in the instruction table. Output Block (Lee, 2017) The output block provides the means to send data or other signals back to the outside world. An actuator is a device that alters a physical quantity. It is commonly driven by a voltage that may be converted from a number by a digital-to- analog converter (DAC) and is packaged with a DAC. Light-Emitting Diodes - provide a way for the system to provide a visual indication via light. Motor Control - applies a torque to a load proportional to the current through the motor windings. o DC Motor - uses a driver circuit and starters to increase torque. ▪ H-bridge is an electronic circuit that can drive the motor in both directions in which it uses four transistors that the schematic diagram appears like an “H”. o Stepper Motor - is a brushless, synchronous electric motor that converts digital pulses into mechanical shaft rotations. Each rotation of a stepper motor is divided into a set number of steps. o Servo Motor - consists of several main parts, the motor and gearbox, a position sensor, an error amplifier and motor driver, and a circuit to decode the requested position. ▪ A technique called pulse width modulation (PWM) can efficiently deliver large amounts of power under digital control. References: Delkin Industrial. (2021, June 9). Understanding embedded memory systems [Article]. Retrieved on July 7, 2021, from https://www.delkin.com/blog/understanding-embedded-memory-systems/ Lee, E., Seshia, S. (2017). Introduction to embedded systems: A cyber-physical systems approach (2nd ed.). MIT Press. Marwedel, P. (2018). Embedded system design: Embedded systems, foundations of cyber-physical systems, and the Internet of Things (3rd ed.). Springer International. Pan, T., Zhu, Y. (2018). Designing embedded systems with Arduino: A fundamental technology for makers. Springer. SiP, SoC, SoM, CoM—What’s the Difference? In allaboutcircuits.com. Retrieved on June 4, 2021, from https://www.allaboutcircuits.com/news/sip-soc-som-comwhats-the-difference/ 03 Handout 1 *Property of STI  [email protected] Page 3 of 3