basic concepts
EEPROM is an acronym for "Electrically Erasable Programmable Read-Only Memory", i.e., Electrically Erasable Programmable Read-Only Memory. With respect to UV in terms of rom erased. However, a variety of variations exist today EEPROM, into a generic name for a memory. Rom the features of this is a random access and modify any byte can be written in each bit to 0 or 1. This is the most traditional kind of EEPROM, data after power is not lost, you can save 100 years, you can erase 100w times. High reliability, but the circuit complexity / cost is high. Therefore, the current EEPROM are tens of kilobytes to a few hundred kilobytes, rarely have more than 512K of. However, the high stability of the equipment above, or a necessity. Also a lot of people use.
Interface Type
EEPROM is generally divided into two types of interfaces: SPI and I2C.
SPI four-wire interface, such as model AT25XXX. Typical hardware circuits:
I2C 2-wire interface, such as model 24CL02 / 04 / XX typical hardware:
Here directly in accordance with standard protocols SPI and I2C protocols can be, the only difference is that they address some of the common and different Flash, facing the need to see the user's manual
EEPROM operation -SPI interface and the I2C interface - voyage way ing - blog Park read and write, pay attention to several issues in front of the linked article written very clearly, and I here do not repeat them.
Examples of software
I did this test equipment, need to implement it on stm32 f4 series of operations, the overall functionality have been delivered to customers, as it relates to confidential company projects, not posted code. A friend in need, please refer to the code below, the following few very good, facing these operations can basically write about.
GitHub - nimaltd/EEPROM: EEPROM emulation for stm32.
GitHub - nimaltd/EEPROM24xx: 24xx EEPROM library for stm32 HAL
GitHub - sinadarvi/SD_HAL_AT24: This library is based on I2C HAL Drivers of STM32 for AT24 EEPROM
Way to be advertising, ah, do flash this aging test please contact a friend, I do flash of aging test equipment research and development, product has come out. Welcomed the inquiry and trial.