EERAM is SRAM and EEPROM on one chip
You can almost hear them think in Microchip’s New Products kitchen: what if we put SRAM and EEPROM on one chip? What would you get? Interesting texture? Exciting flavour? What the heck, lets just do it. Sometimes experiments like this turn out bad, but not this time. The result is EERAM, the cheapest non-volatile SRAM technology currently on the market. No external power needed to keep the contents alive, combined with unlimited writing.
You can almost hear them think in Microchip’s New Products kitchen: what if we put SRAM and EEPROM on one chip? What would you get? Interesting texture? Exciting flavour? What the heck, lets just do it.
Sometimes experiments like this turn out bad, but not this time. The result is EERAM, the cheapest non-volatile SRAM technology currently on the market. No external power needed to keep the contents alive, combined with unlimited writing.
The trick is that the chip’s power supply is constantly monitored. When the voltage drops under a certain threshold, the SRAM contents are quickly copied into the EEPROM; when the power goes up again, the stored data is copied back into the SRAM. Only a small capacitor is needed for supplying the energy required for writing the EEPROM. Of course it is also possible to manually store data into the EEPROM and to read it back whenever it is needed.
The EERAM’s capacity is limited to 16 kilobit but it may be expected that this will go up in the future. A typical Moore’s law thing. The first devices communicate over I²C, SPI will probably follow later.
Sometimes experiments like this turn out bad, but not this time. The result is EERAM, the cheapest non-volatile SRAM technology currently on the market. No external power needed to keep the contents alive, combined with unlimited writing.
The trick is that the chip’s power supply is constantly monitored. When the voltage drops under a certain threshold, the SRAM contents are quickly copied into the EEPROM; when the power goes up again, the stored data is copied back into the SRAM. Only a small capacitor is needed for supplying the energy required for writing the EEPROM. Of course it is also possible to manually store data into the EEPROM and to read it back whenever it is needed.
The EERAM’s capacity is limited to 16 kilobit but it may be expected that this will go up in the future. A typical Moore’s law thing. The first devices communicate over I²C, SPI will probably follow later.
