Type | Volatile? | Writeable? | Erase Size | Max Erase Cycles | Cost (per Byte) | Speed |
SRAM | Yes | Yes | Byte | Unlimited | Expensive | Fast |
DRAM | Yes | Yes | Byte | Unlimited | Moderate | Moderate |
Masked ROM | No | No | n/a | n/a | Inexpensive | Fast |
PROM | No | Once, with a device programmer | n/a | n/a | Moderate | Fast |
EPROM | No | Yes, with a device programmer | Entire Chip | Limited (consult datasheet) | Moderate | Fast |
EEPROM | No | Yes | Byte | Limited (consult datasheet) | Expensive | Fast to read, slow to erase/write |
Flash | No | Yes | Sector | Limited (consult datasheet) | Moderate (Cheap by Z) | Fast to read, slow to erase/write |
NVRAM | No | Yes | Byte | Unlimited | Expensive (SRAM + battery) | Fast |
[1] Barr, Michael. "Memory Types," Embedded Systems Programming, May 2001, pp. 103-104.
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