The 8pins (4 pins on each sides) with 25P05VP、25P10VP、25F512、25F1024、25F1024AN、SST25VF512、SST25VF010, etc. are the BIOS.
Google quickly showed the answer for the first chip, 25P05VP. Have you actually done a search for the information?
Yes, I searched and it says serial flash memory and I don't know what type of memory it is.
well, perhaps Google can help with that, too?
I'm just very curious why you would like to know.
Datasheets will usually specify.
@cloudff1987
What all this has to do with Arduino forum?
BIOS = 'basic input output system'. The term is generally used for the firmware on a computer mainboard. A hard drive as such is generally not regarded as having a 'BIOS'.
That's basically what you call 'BIOS', so forget about the difference.
You can assume that a hard drive (the mechanical kind) will have firmware that acts as an interface between the host computer and the hardware implementation of the drive itself.
The firmware will consist roughly speaking of three parts, like virtually any embedded program:
1: The program code. This does not have to be changed in principle, although modern drives of course to allow for firmware updates. In old drives, this would have been programmed in ROM or EPROM, but today flash memory is the likely candidate. This aligns with the type of IC's you mentioned.
2: Constants; i.e. unchanging data. Generally stored in the same space as the program code.
3: Persistent variables. This would include SMART parameters that record e.g. usage and health statistics. These need to be updated as the drive is used and retain their values through power cycles. It's possible flash is used for this as well, although I expect these variables will be stored in some kind of EEPROM, possibly embedded within the microcontroller itself.
There are several ways to implement the above and although industry will have likely evolved into one or two 'default' topologies, it's hard to say in absolute terms how it's done for any given drive out there.
Be that as it may, I do not expect that it's common that persistent variables like SMART data are stored in the (flash memory) program storage space.
Good question.
the firmware and bios are the same file?
SMART is inside the main processor and not in the flash or eprom?
What type of flash memory is used to store firmware/bios? Is it a single chip?
You'll have to re-read my former comment more diligently.
Neither is a 'file' as such. A hard drive doesn't have a 'BIOS' as such.
That's not a meaningful statement. 'SMART' is a set of functionalities that comprises usage and health monitoring by the drive, record keeping of these parameters and interfacing with the host system to make this data available to the user, create alerts and/or take automated measures to protect data integrity. So you can't really say "SMART is inside the main processor". By definition, the set of routines and data that constitute the SMART functionality is distributed over several hardware and software elements of the drive itself as well as the host system.
EPROM hasn't been used in this context for decades now. I wrote (read more carefully) that I expect EEPROM might be used to store SMART-related data by the drive. This EEPROM might be a discrete component or it may be embedded into the controller.
See above.
Again: what are you trying to accomplish here?
I'm not saying that the firmware/bios is stored inside the HDD disks but in some chip inserted in the PCB (every 2.5" and 3.5" HDD has bios or firmware) I would like to find out what kind of chip technology on the hard disk PCB is used to store smart bios/firmware
Nobody said this.
Please apply this to all posts. There's a systematic problem going on here and it's not on my end.
Why?
Different things! SMART data is likely not stored in the same place as firmware. There's no BIOS.
For firmware: flash
For non-volatile storage of e.g. SMART data: likely EEPROM, possibly FRAM
For volatile parameters, including some run-time SMART data: RAM inside the microcontroller and/or possibly FRAM in modern drives.
The answers to your questions are very specific to the hardware used on a particular hard drive. Without specifying a specific hard drive, and possibly even a specific revision of a particular hard drive, only generalized answers can be suggested.
Looks like the 'person' (?) you've been talking to was referencing this website:
All of the 8pins (4 pins on each sides) with 25P05VP、25P10VP、25F512、25F1024、25F1024AN、SST25VF512、SST25VF010, etc. are the BIOS. It is easy to be found, because there are not many 8pins chips on the PCB.
It continues to state:
If there is no matching 8pins BIOS chip on the PCB, it means the BIOS is integrated on the Main Chip IC.
Some further rooting around suggests this is incorrect; it used to be that way for some drives, but today, it's common that SMART data is in fact:
...i.e. in a dedicated service area on the actual platters, where it's written in a way that's more fault-tolerant.
So firmware ("BIOS" if you must...) is either in a dedicated flash* chip or inside the main controller's flash* .
SMART data is (mostly) in the service area of the actual disk/platters.
*I previously wrote EEPROM here, but this was evidently a slip of the keyboard.
On 2.5" and 3.5" Seagate WD, HGTS, Toshiba HDDs, is the firmware (BIOS) still recorded in eeprom and not in flash?
I thought that the smart was saved on the same chip as the firmware (BIOS) and not inside the magnetic disks
Hundreds of individual models, probably thousands, match this description, from the era early 1990s to present. Among these, there will likely be significant differences in how firmware as well as diagnostic data are/were stored.
I'm sorry about a former typo; this will be typically in flash memory, not EEPROM. Either in a separate chip or as part of the controller IC.
Apparently it's now stored mostly on the platters.
What type of flash memory stores firmware/bios?
When the firmware/bios is inside the controller IC, would it be another flash memory inside this main chip?
What do you mean by 'type'?
If the firmware is inside the controller IC, it would be stored in flash memory in that IC, yes. Not sure what you're asking though; it seems tautological.
flash memory used in pcb hdds 2.5" and 3.5" is flash nand?
Search for the datasheet; it might tell you. This one doesn't seem to indicate which type of flash: W25P10,20,40 Datasheet by Winbond Electronics | Digi-Key Electronics. It however does state the data retention of 20 years.
I do not think that it's relevant if it's NAND flash or NOR flash unless it's to satisfy your curiosity. nand flash vs nor flash - Google Search