MEMORY TECHNOLOGY

MEMORY TECHNOLOGY

All microprocessor/microcontroller need memory, RAM and ROM are the basic for any microcontroller/microprocessor design. The table below shows the types of memories available.

Types of memory in microcontrollers

Random Access Memory (RAM): Random Access Memory (RAM) is a type of memory used for temporary storing data and intermediate results created and used during the operation of the microprocessor or microcontrollers.

Read Only Memory (ROM): Read Only Memory (ROM) is a type of memory used to permanently save the program being executed. The size of the program that can be written depends on the size of this memory.

EPROM (UV Erasable Programmable Read Only Memory): This is a special type of ROM that is programmed electrically and yet is erasable under UV light.

Electrically Erasable Programmable ROM (EEPROM): The EEPROM is a special type of memory not contained in all microcontrollers. Its contents may be changed during program execution (similar to RAM), but remains permanently saved even after the loss of power (similar to ROM).

EEPROM (Electrically Erasable Programmable ROM): This offer users excellent capabilities and performance. Only one external power supply is required since the high voltage for program/erase is internally generated.

OTP (One Time Programmable) EPROM: In most applications, EPROMs are programmed one time and will never have to be erased.

Parallel/ Serial EEPROM: There are two distinct EEPROM families: serial and parallel access. The serial access represents 90 percent of the overall EEPROM market, and parallel EEPROMs about 10 percent. Parallel devices are available in higher densities (≥256Kbit), are generally faster, offer high endurance and reliability, and are found mostly in the military market.