• Cache hit o A requested instruction or data is in cache o Cache performance is high when cache hit rate is high • Cache miss o A requested instruction or data is not in cache o Cache performance is low when cache miss is high • Line fill o Retrieving data from external memory to cache in case of cache miss o Caches retrieve a complete line | Amr Ali Abdel-Naby@2010 Embedded Systems Structure Embedded Systems Structure Amr Ali Abdel-Naby Embedded Systems Developer amraldo@ +2-012-3600-207 Amr Ali Abdel-Naby@2010 Embedded Systems Structure Outline Composition of Embedded Systems Processor System Bus Memory Devices Peripherals Amr Ali Abdel-Naby@2010 Embedded Systems Structure Part I: Embedded Systems Structure Composition of Embedded Systems Processor System Bus Memory Devices Peripherals Amr Ali Abdel-Naby@2010 Embedded Systems Structure What is an Embedded System? A system composed of HW + SW to perform a dedicated function. On average, a human being meets 100s of embedded systems daily Amr Ali Abdel-Naby@2010 Embedded Systems Structure Embedded System Components Processor Memory Devices I/O Devices Application SW Operating System Device Drivers HW SW Amr Ali Abdel-Naby@2010 Embedded Systems Structure Part I: Embedded Systems Structure Composition of Embedded Systems Processor System Bus Memory Devices . | Amr Ali Abdel-Naby@2010 Embedded Systems Structure Embedded Systems Structure Amr Ali Abdel-Naby Embedded Systems Developer amraldo@ +2-012-3600-207 Amr Ali Abdel-Naby@2010 Embedded Systems Structure Outline Composition of Embedded Systems Processor System Bus Memory Devices Peripherals Amr Ali Abdel-Naby@2010 Embedded Systems Structure Part I: Embedded Systems Structure Composition of Embedded Systems Processor System Bus Memory Devices Peripherals Amr Ali Abdel-Naby@2010 Embedded Systems Structure What is an Embedded System? A system composed of HW + SW to perform a dedicated function. On average, a human being meets 100s of embedded systems daily Amr Ali Abdel-Naby@2010 Embedded Systems Structure Embedded System Components Processor Memory Devices I/O Devices Application SW Operating System Device Drivers HW SW Amr Ali Abdel-Naby@2010 Embedded Systems Structure Part I: Embedded Systems Structure Composition of Embedded Systems Processor System Bus Memory Devices Peripherals Amr Ali Abdel-Naby@2010 Embedded Systems Structure The Processor The core of a digital system AKA CPU Performs arithmetic, control, data, and I/O operations A small IC that embeds everything a CPU needs is called a microprocessor. Nowadays, this IC is called a SOC Amr Ali Abdel-Naby@2010 Embedded Systems Structure The Processor Structure Registers ALU: Arithmetic Logic Unit CU: Control Unit Internal Bus CU ALU Registers Internal Bus Amr Ali Abdel-Naby@2010 Embedded Systems Structure Registers Temporal storage inside the CPU Flip-flops + latches General purpose register Carry out program or data processing Control register Controls the program or the processor Program Counter (PC), Status/flag register Shows the current state of the processor Amr Ali Abdel-Naby@2010 Embedded Systems Structure ALU Arithmetic operations +, -, Logical operators AND, OR, Writes operation results to the status register or the flag register Carry occurrence, overflow occurrence, Amr Ali .
