 This is the video based on architecture of embedded system hardware approach. Learning outcomes, at the end of this video you will be able to draw the building blocks of hardware architecture of an embedded system. You will be able to describe functional importance of each block in hardware architecture of an embedded system. You will be able to differentiate between risk and SISC processor architectures. These are the contents introduction. Embedded system can be defined as a computing device that does a specific defined job. For example, air conditioner, VCD player, DVD player, mobile phones, then fax machines etc. So, these are the different embedded systems that we have shown out here. Each appliances will have a processor and hardware along with embedded software. Hardware, hardware is to meet the specific requirement of applications along with embedded software. Software is executed by the processor by meeting that specific requirement. This is the hardware architecture where at the center CPU, the heart of the hardware architecture is a CPU. The different blocks are sensors, LCD, LED displays, then function keypad, communication interface, memory unit, RAM and ROM. There is a debug port as well, watchdog timer and reset circuitry, chip select, clock circuitry, power supply unit and analog to digital converters, ADC, digital to analog converter, DAC. First as CPU is the heart of the architecture, let us look at the CPU part which is central processing unit. What basically happens in CPU is the arithmetic and logical operations using ALUs and for these operations it needs the help of the general purpose resistors. From which it can take the data and operate on that and perform the operations. Along with this CPU also consists of one control unit. In this control unit, there are two different sections of memory. One is the address resistor, memory address resistor, other is the memory data resistor. The instructions which are pointed by the instruction pointer, those instructions will be fetched and these instructions will be decoded by the instruction decoder and then these instructions will be executed and in case if the interrupt happens in between address location of the instruction pointer need to be stored on the stack and so the stack pointer points the location of the stack where the address of the instruction pointer is stored. In memory address resistor which is from this the address bus is going, this address bus is the unidirectional and from memory data resistor which accesses the data to and through that means it can take the data, it can send the data, so data bus is bidirectional and the bus from instruction decoder that you can see is a control and status bus. Processor architectures. Based on number of program and data buses used, there are three types of architectures for processors. Von Neumann architecture, Harvard architecture, Super Harvard architecture. Von Neumann architecture is shown here in which there is single memory to store the instructions as well as data. The CPU and memory are interacted with the help of address and data buses but there is a use of single memory chip to store both instructions and data and so that this architecture in is one of the simple architecture as it is simple it is widely used architecture. Harvard architecture is the next one in which we can see there is a separate program memory and separate data memory. Two separate memory blocks that is program memory and data memory. Program memory is to store the instructions and data memory stores only data. This architecture is much efficient because the instructions and data will be processed at at the same time or simultaneously and so that this architecture is faster compared to Von Neumann architecture. The modification to the Harvard architecture is the Super Harvard architecture. Here also we can see two memory blocks are there program memory address bus program memory data bus the separate address bus and data buses for data memory and for program memory but what is the modification? The modification is that it is found that data is accessed frequently so some secondary data is stored in the program memory in order to balance both the memory blocks so this is this type of architecture is used in digital signal processes. At this point can you think and write the answer for the question what are the different processor architectures based on number of instruction. You can pause the video for some time and can think about the question and can write down the answer. Thank you I hope you have written the answer. The processor architectures are CISC architecture which is a complex instruction set architecture and RISC architecture which is reduced instruction set architecture. As the name suggests reduced instruction less number of instruction set is there complex instructions the instructions huge number of instruction set is there in the architecture. We can differentiate between what is CISC and RISC architecture so CISC architecture contains many complex instructions whereas RISC architecture has simple instructions which are few in number. The instructions are variable in length on this side the instructions are fixed length. Here the single register set is needed typically 6 to 16 registers whereas here multiple registers are often more than 256 registers are there. Instructions of variable number of bytes here the instructions of few number of bytes is there. Instructions more clock cycles here single clock clock cycle instructions are there. This is here the efficient use of RAM is done compared to RISC whereas here the heavy use of RAM is done. Here as the number of instructions are more or complex there is a the when we are writing the coding part the there is a reduction in software complexity by increasing the complexity of processor architecture. Here software is complex as less number of instructions are there the software is going to be complex at the same time the processor architecture is simple. Here no pipeline or very less pipelining is there whereas RISC is highly pipeline. The examples of CISC architecture are Intel x86 family Motorola 68000 family whereas on this side ARM at mail AVR microchip spark all these are from RISC architecture. Again look at the hardware architecture why again came to the same block diagram because we talked about the CPU CPU class the classifications of the processors. We talked about the memory so let us talk about the memory more. Here RAM and ROM memory is shown. RAM is the random access memory ROM is the read only memory. RAM is used for usual execution of the program and for the instructions ROM on which the stored instructions will be permanent which is used to store the firmware of an embedded system. Debug port is the port provided for debugging part then watchdog timer and reset circuitry. On the embedded system there can be a separate reset button when it sprays the system reset but at the same time the watchdog timer is there watchdog timer is set to some high value if everything is going fine the timer is going to decrement and intermittently it is going to be again set to large value. So timer is going to decrement and when it expires if any problem occurs when it expires the system resets. Chip select the processor is connected to number of peripherals and the process can be identified the particular process can be identified with the help of chip select. Clock circuitry the clock is provided to one of the pen and the processor and all the events happens at the clock and if the clock frequency is high the processor is faster. Let us look at this power supply unit elements of the embedded system works at plus 12 volt plus 5.5 volt minus 5 volts and plus 3.3 volts power supply DC power supply. So this power supply unit will provide a stabilized DC power supply to the elements of this of the embedded system ADC ADC takes the analog data converts it into the digital form and DAC does the opposite digital data is converted into analog form from where the analog data is coming thus from the sensors. Sensors take the real life for the real input which is in from the environment and can be given to the processor and before it is given to the processor if it is in the analog form it need to be converted into digital sensors are actually converting real-time data or the actual data into the electrical signal. LED LCD these are the outputs and devices for the embedded system liquid crystal display and LEDs these are the giving the visual indications of the events happening in the embedded system. Functional keypad the keypad can be designed to perform a particular function and then accordingly this keypad can be interfaced with the processor and we can use this to do the particular task as per our need. Communication interface the processor communicates with the outside world with the help of communication interface the communication interface such as RS-232, RS-422, Bluetooth, Wi-Fi then it can be Ethernet all these are the communication interfaces. The references are which are used is KVKK Prasad embedded real-time system and ARM system developer guide by Andrew Schloss. Thank you.