There are different types of electrical interfaces to EEPROM devices. Main categories of these interface types are:
1)Serial bus 2)Parallel bus
1)Serial bus devices:-Most common serial interface types are SPI, I²C, Microwire, UNI/O, and 1-Wire. These interfaces require between 1 and 4 control signals for operation, resulting in a memory device in an 8 pin (or less) package.The serial EEPROM (or SEEPROM) typically operates in three phases: OP-Code Phase, Address Phase and Data Phase. The OP-Code is usually the first 8-bits input to the serial input pin of the EEPROM device (or with most I²C devices, is implicit); followed by 8 to 24 bits of addressing depending on the depth of the device, then data to be read or written.Each EEPROM device typically has its own set of OP-Code instructions to map to different functions. Some of the common operations on SPI EEPROM devices are:
a)Write Enable (WREN) b)Write Disable (WRDI) c)Read Status Register (RDSR) d)Write Status Register (WRSR) e)Read Data (READ) f)Write Data (WRITE)
1)Serial bus 2)Parallel bus
1)Serial bus devices:-Most common serial interface types are SPI, I²C, Microwire, UNI/O, and 1-Wire. These interfaces require between 1 and 4 control signals for operation, resulting in a memory device in an 8 pin (or less) package.The serial EEPROM (or SEEPROM) typically operates in three phases: OP-Code Phase, Address Phase and Data Phase. The OP-Code is usually the first 8-bits input to the serial input pin of the EEPROM device (or with most I²C devices, is implicit); followed by 8 to 24 bits of addressing depending on the depth of the device, then data to be read or written.Each EEPROM device typically has its own set of OP-Code instructions to map to different functions. Some of the common operations on SPI EEPROM devices are:
a)Write Enable (WREN) b)Write Disable (WRDI) c)Read Status Register (RDSR) d)Write Status Register (WRSR) e)Read Data (READ) f)Write Data (WRITE)
Other operations supported by some EEPROM devices are:-
a)Program b)Sector Erase c)Chip Erase commands2)Parallel bus devices:-Parallel EEPROM devices typically have an 8-bit data bus and an address bus wide enough to cover the complete memory. Most devices have chip select and write protect pins. Some microcontrollers also have integrated parallel EEPROM.Operation of a parallel EEPROM is simple and fast when compared to serial EEPROM, but these devices are larger due to the higher pin count (28 pins or more) and have been decreasing in popularity in favor of serial EEPROM or Flash.
No comments:
Post a Comment