Electrical interface EEPROM

1 electrical interface

1.1 serial bus devices
1.2 parallel bus devices
1.3 other devices

electrical interface

eeprom devices use serial or parallel interface data input/output.

serial bus devices

the common serial interfaces spi, i²c, microwire, uni/o, , 1-wire. these use 1 4 device pins , allow devices use packages 8-pins or less.

a typical eeprom serial protocol consists of 3 phases: op-code phase, address phase , data phase. op-code first 8-bits input serial input pin of eeprom device (or i²c devices, implicit); followed 8 24 bits of addressing depending on depth of device, read or write data.

each eeprom device typically has own set of op-code instructions mapped different functions. common operations on spi eeprom devices are:

write enable (wrenal)
write disable (wrdi)
read status register (rdsr)
write status register (wrsr)
read data (read)
write data (write)

other operations supported eeprom devices are:

program
sector erase
chip erase commands

parallel bus devices

parallel eeprom devices typically have 8-bit data bus , address bus wide enough cover complete memory. devices have chip select , write protect pins. microcontrollers have integrated parallel eeprom.

operation of parallel eeprom simple , fast when compared serial eeprom, these devices larger due higher pin count (28 pins or more) , have been decreasing in popularity in favor of serial eeprom or flash.

other devices

eeprom memory used enable features in other types of products not strictly memory products. products such real-time clocks, digital potentiometers, digital temperature sensors, among others, may have small amounts of eeprom store calibration information or other data needs available in event of power loss. used on video game cartridges save game progress , configurations, before usage of external , internal flash memories.