chetan shidling answered 4 years ago
There are eight types of memories used in the embedded system:
- Static Random Access Memory (SRAM)
- Dynamic Random Access Memory (DRAM)
- Masked ROM
- PROM
- EPROM
- EEPROM
- Flash Memory
- NVRAM Or Non-Volatile Random Access Memory
01. SRAM or Static Random Access Memory – The SRAM is 4 times faster than DRAM. The cost of SRAM is high compared to DRAM. In DRAM, we need to refresh the data continuously whereas in SRAM we do not need to refresh data.
02. Dynamic Random Acces Memory or DRAM – The DRAM is 4 times slower than SRAM. The cost of DRAM is low compared to SRAM. In DRAM, we need to refresh the data continuously.
Both SRAM and DRAM are primary memory.
03. Masked ROM – In Masked ROM, the data is stored at the beginning only when the memory is manufactured and the data can not be deleted once stored. Used in long term devices.
04. PROM – In PROM or Programmable Read-Only Memory, the memory can be programmed only one time and it can not be erased and reprogrammed.
05. EPROM – EPROM stands for Erasable Programmable Read-Only Memory, the memory can be reprogrammed again with new data. The memory has a glass window on the top, when it is exposed in the sunlight, the data stored in memory will erase.
06. EEPROM – EEPROM stands for Electrically Erasable Programmable Read-Only Memory, the memory can be reprogrammed again with new data. The data in the memory can be erased electrically and can be reprogrammed with the new data.
07. Flash Memory – The Flash memory has all qualities of EEPROM, but the EEPROMs are reprogrammable one bit at a time, while the flash memory reprogrammable one block at a time and the size will be given in the specification.
08. NVRAM Or Non-Volatile Random Access Memory – The NVRAM is a special type of memory like SRAM with supply (power) and the data can not be deleted, it is stored permanently. The NVRAM is more costly compared to all types of memories mentioned above.
These are the different types of memories.