1. System Interconnection
1.1. some mechanism that provides for communication among CPU, main memory, 1/0
2. CPU
2.1. ALU (Arithmetic Logic Unit): Handles mathematical and logical operations
2.2. Registers: Temporary memory, provide storage internal to the CPU
2.2.1. Accumulator (AC): Stores the intermediate results of arithmetic and logical operations.
2.2.2. Program Counter (PC): Holds the address of the next instruction to be executed
2.2.3. Instruction Register (IR): Stores the current instruction being decoded and executed
2.2.4. Memory Address Register (MAR): memory address storage
2.2.5. Memory Data Register (MDR): Store data read or written to memory
2.2.6. General Purpose Registers (GPRs): General purpose registers are used to store temporary data.
2.2.7. Stack Pointer (SP): Holds the top address of the stack
2.3. Control unit: Controls and coordinates computer operations
2.3.1. Sequencing Logic: Controls the order in which commands are executed.
2.3.2. Control Unit Registers and Decoders: Store and decode instructions.
2.3.3. Control Memory: Store micro-operations to execute commands
2.3.4. Coordinate CPU operations Decode commands andgenerate control signals. Manages data flow within the CPU and with memory
3. I/0
3.1. Input Devices: such as keyboards, mice, scanners.
3.2. Output Devices: such as monitors, printers, speakers.
3.3. Receive data Export results Coordinates the flow of data between the CPU and peripheral devices
4. Main memory
4.1. Cache Memory: -Small Capacity -Cache is faster than main memory -Temporary data storage close to CPU to reduce data retrieval latency -Cache is placed between the CPU and main memory to increase the speed at which the CPU accesses memory.
4.1.1. L1 Cache ( Level 1)
4.1.1.1. Fastest, located inside CPU Small size (about a few KB)
4.1.2. L2 Cache (Level 2)
4.1.2.1. Slower than L1 but faster than L3 Larger in size than L1 (several hundred KB to several MB) Can be located inside or outside the CPU
4.1.3. L3 Cache (Level 3)
4.1.3.1. Slowest of all caches, but faster than RAM Large in size (a few MB to tens of MB) Mainly used to support L1 and L2
4.2. Internal Memory Faster Access External Memory Temporarily stores data needed by the CPU when executing a program Moderate capacity
4.2.1. RAM
4.2.1.1. DRAM (Dynamic RAM)
4.2.1.1.1. Memory cell stores binary data using charge in capacitor - There is charge on capacitor - bit 1 - There is no charge on capacitor - bit 0 Needs to periodically charge to maintain data storage. “Dynamic” is understood as the tendency of the charge on the capacitor to leak even when constantly powered.
4.2.1.1.2. SDRAM
4.2.1.1.3. DDR-DRAM
4.2.1.1.4. RDRAM
4.2.1.2. SRAM (Static RAM)
4.2.1.2.1. Binary values stored in flip-flops -> volatile information Retains data as long as power is supplied to it No need to refresh Cache
4.2.2. ROM
4.2.2.1. PROM (Programmable ROM)
4.2.2.1.1. Less expensive alternative Nonvolatile and may be written into only once Writing process is performed electrically and may be performed by supplier or customer at a time later than the original chip fabrication Special equipment is required for the writing process Provides flexibility and convenience Attractive for high volume production runs
4.2.2.2. EPROM (Erasable Programmable ROM)
4.2.2.2.1. Erasable programmable read-only memory Erasure process can be performed repeatedly More expensive than PROM but it has the advantage of the multiple update capability
4.2.2.3. EEPROM (Electrically Erasable Programmable ROM)
4.2.2.3.1. Electrically erasable programmable read-only memory Can be written into at any time without erasing prior contents Combines the advantage of non-volatility with the flexibility of being updatable in place More expensive than EPROM
4.2.2.4. Flash ROM
4.2.2.4.1. Intermediate between EPROM and EEPROM in both cost and functionality Uses an electrical erasing technology, does not provide byte-level erasure Microchip is organized so that a section of memory cells are erased in a single action or “flash”
4.3. External Memory: -Large capacity, used for long-term data storage -Access speed is slower than Internal Memory
4.3.1. HHD (Hard Disk Drive) -A magnetic disk is a circular platter made of a non-magnetic material, called the substrate, coated with a layer of magnetic material. -The substrate is usually aluminum or aluminum alloy.
4.3.1.1. -Large capacity (hundreds of GB to several TB) -Access speed is slower than SSD -Has mechanical components (magnetic disk, read head)
4.3.2. SSD (Solid State Drive): SSD is a semiconductor memory device that can be used as a replacement for a hard disk drive (HDD). 2 special types of flash memory: -NOR -NAND
4.3.2.1. -Faster than HDD, no mechanical parts -Uses flash memory to store data Large capacity (hundreds of GB to several TB)
4.3.3. Optical Drive (CD/DVD: is a device that reads and writes data from optical discs.
4.3.3.1. -Stored on optical disc, smaller capacity than HDD and SSD -Used for temporary data storage or backup
4.3.4. USB FLash Drive
4.3.4.1. Portable storage, easy to connect and use Moderate capacity (a few GB to hundreds of GB)