▷ What is nvram and what is it for

In this article we will dedicate ourselves to explaining in the best possible way what NVRAM is and what functions they have on our computer.

As many of you know how to talk about hardware, it is to fully enter the physical functioning of our computer, know its components and know how they work. Prepared? We explain what NVRAM is !

Index of contents

Learning about the components that make up our computer will always help us understand a little better how they work. If we had to talk about each of the components that make up our team, we would be here for several months learning and writing, without having surely learned a quarter of what this element is. They are such highly complex machines that only those who have been in charge of creating their architecture are able to understand how they really work. Quite possibly even they are not able to explain to others about it.

For our part, it is not that we intend to do any of this, but we can focus on some of the most outstanding components of a smart device and explain what they are and some of their functions. Or even the way to interact with them, and that is what we will do today with NVRAM.

What is NVRAM

The NVRAM or " Non-Volatile Random Access Memory ", non-volatile random access memory in our beloved Spanish, is a random access memory that is capable of storing information and not losing it when removing the component's power supply.

These types of memories are currently built using semiconductor chips and are present in practically all electronic devices that require firmware to function. This includes personal computers, phones, routers, and all programmable devices.

The information stored by NVRAM is used by the device's operating system or firmware so that, during the boot process, the basic operating configuration of the device can be loaded. This can include, boot configuration of hard drives, input and output devices, volume, time and date, and other basic parameters.

NVRAM Technologies

The fact of having to store certain configuration data to start a computer has always been necessary, and this is why there have been different technologies

• EAROM: Electrically Alterable Read Only Memory. This type of memory is read only and to erase its content we must apply an electrical voltage. EEPROM: Electrically Erasable Programmable Read-Only Memory. This type of ROM is, in addition to being erasable, also electrically reprogrammable, but bit by bit. EPROM and flash EEPROM: this type of ROM memory is the evolution of the previous ones, since it allows reading and writing in multiple memory locations encapsulated in a flash chip. This allows a much faster operating speed than previous technologies.

Basically two different strategies have been developed to achieve quick access memories and unlimited reading cycles:

• Dallas Semiconductor NVRAM: That type of circuit integrates a low-power CMOS RAM, along with a lithium battery and a controller that defines a voltage monitor to establish read and write cycles. In addition, they contain a real-time clock to synchronize the operating cycles. These memories can be working with practically the same lithium battery for up to ten years, due to their low NVRAM consumption made up of a RAM together with an EEPROM: these chips allow reading and writing through the built-in RAM using a retention pulse. The content of the RAM goes directly to the EEPROM where the data will be stored without the need for external power even beyond ten years. When the computer is running, the data stored in the EEPROM is passed back to RAM for faster access and writing.

NVRAM and BIOS

After reading this, we will all have realized that the BIOS of our team is encapsulated precisely in a CMOS chip that really is an NVRAM. This program remains on our computer even when it is stopped and disconnected from power.

As we have seen, a lithium battery is needed to keep the configuration of our equipment stored for when it starts up. But in addition to this, we must take into account one important thing, and it is the one discussed above. If we remove the battery from the motherboard, at no time are we clearing the BIOS of our computer. The only thing we will achieve with this is to delete the equipment configuration stored in NVRAM

If we now started the computer, we would receive a message notifying us that we must enter the BIOS to establish the operating parameters of our computer. in this way, this configuration would be loaded again in NVRAM so that, on the next restart of the equipment, it would load normally.

In the NVRAM of the BIOS they will store the parameters referring to input and output devices, parameters of the CPU, RAM and hard drives and system boot parameters such as date and time, etc.

Difference Between NVRAM AND SSD

At this point, we could think that SSD hard drives are also NVRAM, since we know that the information stored in them remains unchanged despite completely removing power from the device.

They really are, that we could talk about NVRAN in these devices and in USB storage drives, but this term is more related to the type of memories and technologies used for BIOS, UEFI and firmware chips of other devices.

In the case of SSDs, non-volatile memory is used but based on NAND gates, which are natively capable of storing information due to their memory status.

If you want to know more information about what an SSD is and how it works, you can read our tutorial on this topic.

In this way we have been able to learn what an NVRAM is and its applications and operation. You will also see interesting:

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