Embedded System – Definition & Architecture

Definition: An embedded system is a computing system designed to perform dedicated functions within a larger mechanical/electrical system, with tight constraints on cost, size, power, and real-time response. It contains a microprocessor/microcontroller, memory, I/O, and firmware.

Architecture Block Diagram (describe):

[Sensors/Input]→[Signal Conditioning]→[ADC]→|    Central Unit    |→[DAC/Drivers]→[Actuators/Output]
                                      |  Processor (8051/ARM) |
                                      |  Memory: ROM/Flash,   |
                                      |   RAM, Cache          |
                                      |  Timers/Counters,     |
                                      |  Interrupt Controller |
                                      |  Communication: UART, |
                                      |  SPI, I2C, USB, ETH  |
                                      |  I/O Ports, Power Mgmt|
                                      +-----------+------------+
                                                    |
                                             [Software/Firmware]

Components:

1. Processor core: 8051, ARM, AVR, PIC – executes firmware.
2. Memory: Program Flash/ROM, Data RAM, EEPROM for parameters.
3. I/O & Peripherals: GPIO, timers, ADC/DAC, PWM, interrupts.
4. Sensors/Actuators: Input physical signals, output control.
5. Communication: RS232, I2C, SPI, CAN, USB, Zigbee/BT for connectivity.
6. Power & Clock: Oscillator, reset, power management.
7. Software: Real-time OS or bare-metal C/assembly.

Characteristics: Single function, real-time, resource-constrained, reliable, low cost. Examples: Washing machine, automotive ECU, medical device.