Electrically erasable programmable read only memory
Electrically erasable programmable read-only memory (EEPROM) chips are similar to PROM devices, but require only electricity to be erased. Architecture or status, performance, power characteristics, and packaging information are all important parameters to consider when searching for EEPROM memory chips.
Architecture or status specifications that are important to consider when searching for EEPROM memory chips include density, number of words, bits per word, bus type, and production status. Density is the capacity of the memory chip expressed in bits. Number of words refers to the number of “rows” in the organization of the memory chip. Each row stores a memory word and connects to a word line (one line of the memory bus) for addressing purposes. Bits per word refer to the number of “columns” in the organization of the memory chip. Each column connects to a sense / write circuit (a bit), which connects to data input/output lines of the chip. Common choices for bus type include parallel, serial, serial-1wire, serial-2 wire, serial-3 wire, I2C, Microwire, SPI, and serial-uPort. Production status can be active, discontinued or new. Active EEPROM memory chips are available and are currently being manufactured. Discontinued EEPROM memory chips are no longer available from the manufacturer, but may still be found in the supply chain. New devices are either just hitting the market, or are soon to be, as announced by the manufacturer.