Please enable JavaScript.
Coggle requires JavaScript to display documents.
INTERNAL MEMORY - Coggle Diagram
INTERNAL MEMORY
READ-ONLY
MEMORY
Read Only Memory
Contains a permanent pattern of data that cannot be changed or added.No power source is required to maintain the bit values in memory. Data or program is permanently in main memory & never needs to be loaded from a secondary storage device.
Programmable ROM (PROM)
Less expensive alternative. Nonvolatile & may be written into only once. Writing process is performed electrically and required special equipment. Provides flexibility & convenience. Attractive for high volume production runs.
ERROR CONNECTION
Hard Failure
Caused by harsh environment abuse, manufacturing defects or wear. Permanent physical defect. Memory cell or cells affected cannot reliable store data but become stuck at 0 or 1.
Soft Error
Caused by power supply problem or Alpha particles. Random, non-destructive event that alters the contents of one or more memory cells. No permanent damage to memory.
READ-MOSTLY MEMORY
-
-
Flash Memory
Intermediate between EPROM & EEPROM in both cost & 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"
-
HAMMING ERROR DETECTION
-
Syndrome Word
To start, determine how long the code must be. A bit by bit comparison is done by taking the exclusive-OR of two inputs. The result is called the syndrome word. Each bit of the syndrome is 0 or 1 according to if there is or is not a match in that bit position for the two inputs. The syndrome word is K bits wide & has a range between 0 and 2^k-1.
DRAM VS SRAM
-
Dynamic Cell
Used for main memory. Smaller, simple to built and less expensive. More dense (smaller cells = more cells per unit area). and also requires to supporting refresh circuitry.
-