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Comparison of ROM Types (ROMの種類の比較)

ROM Type Cost Programmability Time to Program Time to Erase
Mask-programmed ROM Very cheap At factory only Weeks N/A
PROM Cheap Once, by end-user Seconds N/A
EPROM Moderate Many times Seconds 20 minutes
Flash EPROM Expensive Many times 100$\mu s$ 1s, large block
EEPROM Very expensive Many times 100$\mu s$ 10ms, byte

David Asano