An embedded system in the computer uses a variety of memory modules meant for different functions. Some are assigned for the storage purpose of software code, while others are used for instructions in the hardware. These operations are used to program the microcontroller.
A memory module is a physical device installed in digital electronics to store data or programs on a permanent or temporary basis. All these memories embedded in a system have their specific mode of operation. With an efficient memory module, the operation of the embedded system is enhanced.
There are many sellers around for selling memory modules, but for electronic items it is always so that online prices are lower than offline prices, so the best online marketplace for sellers are generally the most trustworthy ones.
There are two categories of memory modules used in systems based on the nature of the application. Let’s check them out!
2 Types of Memory Modules Used in the System
There are two types of memory modules used in the embedded system. Read on to find more about them.
Volatile memory, as the name suggests, can hold its content till power is supplied to the system. When the power is cut off, this memory loses the stored content. Computer memory RAM is the main memory chip that enables information to be stored and accessed easily from a random location of the memory module.
RAM, or random access memory, is a collection of the storage cells that can be accessed for information transfer from any location. Every cell consists of MOSFET or BJT, depending on the memory module. For instance, a 4×4 RAM can hoard 4 bits of information.
Non-volatile memory is a storage chip that can store information permanently, even when the power is disconnected. Read-only memory is a good example of non-volatile memory and is typically non-volatile in nature. One can only read from the ROM but cannot write on it.
ROM stores all the instructions that are applicable at the time of operating the computer system. This type of operation is known as bootstrapping. The memory cell of ROM is designed with a single transistor. ROM is not only used in computers, but also in other electronic gadgets, like washing machines, micro ovens, controllers, etc. You can choose from the wide verities of a computer RAM memory for sale at any marketplace.
There are further classifications of both volatile and non-volatile memory modules.
Different Types of RAM Chips
Static Random Access Memory (SRAM)
The SRAM, or static random access memory, stores its memory in data bits as long as it gets the power supply. There is no need for periodic refreshing of the memory, but once the power is switched off, it doesn’t retain the content. It uses bistable latching circuitry to store every bit of information.
Compared to the DRAM, the static RAM provides faster access to data. In an SRAM, every bit is stored in four transistors that form two coupled inverters. There are two extra transistors that manage the access of the storage cells during reading and writing operations. Each of the memory bits is stored in the six transistors used by the SRAM.
Dynamic Random Access Memory (DRAM)
DRAM, or Dynamic Random Access Memory, stores every bit of its data in separate capacitors. It is more efficient compared to SRAM as this requires less physical space to store data. If two memory modules of SRAM and DRAM are compared together, the latter will be able to store more data. It stores its data by assigning it to separate capacitors.
This form of storage is more efficient. However, it comes with a slight drawback, that is, it is power-hungry and requires constant charging to keep its modules running. The DRAM modules can be used to store large amounts of data and execute microprocessor code. It can also be used to run applications that require low latency memory access.
There are other types of memories, and we will discuss them here. The types of ROM memories are:
Programmable Read Only Memory
PROM, or Programmable Read Only Memory, is a type of memory module that can only be modified or changed once by the user. It is made with a group of consecutive fuses.
A very unique or interesting property of this memory module is that the fuse of these modules are burnt. The open or unburnt fuses are read as once while the burnt fuses are read as zeros.
Erasable Programmable Read Only Memory
EPROM or Erasable Programmable Read Only Memory is unique for its kind. This memory module can be reprogrammed as many times as users want to correct the errors. The content of this memory module is also protected and stored until it is exposed to ultraviolet light.
The EPROM memory modules are programmed by using electrical current charge on a small piece of silicon, called polysilicon metal, otherwise known as a floating gate. The floating gate is located in the memory cell.
This process works – when the electrical charge is in the gate the cell is programmed with a 0; when the electrical charge is not in the gate the cell is programmed with a 1.
Electrical Erasable Programmable Read Only Memory
EEPROM, or Electrical Erasable Programmable Read Only Memory, is a user-modified memory module that can be reprogrammed as many times as the user wants. These memory modules are used in both computers and other electronic devices. Their speciality is that they can hold small amounts of data even if the power supply is shut down.
Another fascinating feature of the EEPROM memory module is that its data is stored and removed one bit at a time and not all at once.
The EEPROM cell is commonly created with two transistors. Within this particular memory module, there are two types which are serial EEPROM and parallel EEPROM. Among the two, the parallel EEPROM is faster and more cost-effective than serial EEPROM memory modules.
That concludes a basic understanding of RAMs and the different types of RAMs and their uses and their functionality. So, now you have the knowledge you need to create your own embedded system with your choice of memory modules. You can obtain a computer RAM memory for sale at any marketplace.