74
votes
Saving data without a microcontroller?
You can't use a EEPROM or any other storage means that is digital without first converting your signal to digital. Using a microcontroller is the obvious and simple way to do that.
However, if you ...
- 317k
49
votes
Accepted
Can we not simply connect a battery to a RAM to prevent data loss during power cuts?
Short answer: You might be able to "connect a battery to a RAM to prevent data loss during power outage", but this depends on the type of RAM.
SRAM (Static Random Access Memory) is not DRAM, ...
- 16.6k
37
votes
Saving data without a microcontroller?
No, you can't store an analog value as-is on a digital storage medium like an eeprom or an SD card.
You could do an analog-to-digital conversion (using an appropriate chip) to convert your analog to ...
- 48.9k
31
votes
Best way to store very small amount of data?
Personally I use FRAM, it is easy to use and you can get 32K by 8 for a few dollars. It works like the EEPROM modules but there is no delay or limits on reads and writes. These can be purchased on ...
- 5,506
28
votes
Accepted
Best way to store very small amount of data?
I need to be able to update data multiple times a hour so I expect EEPROM to become useless
Actually... this is not 100% true.
Check your EEPROM datasheet. For a very basic and common EEPROM (for ...
- 1,240
26
votes
Best way to store very small amount of data?
Just pick a bigger EEPROM, and write it sequentially.
Suppose you have a EEPROM family which withstands 10000 write/erase cycles, and you need 100 times more. Then pick a 1 MB EEPROM form the same ...
- 26.2k
25
votes
Can we not simply connect a battery to a RAM to prevent data loss during power cuts?
Can we not simply connect a battery to a RAM to prevent data loss during power cuts? So can you tell me why is this not done?
Of course we do! It's called battery-backed SRAM, and it's widely used in ...
- 7,947
23
votes
Accepted
How can I access more than 15 addresses of data from my 8 bit incomplete computer?
the half of the byte in memory is the opcode and other half is the address
Well, that's one way of doing it, but there are lots of ways of doing it.
Instructions don't have to contain the address. ...
- 47.4k
22
votes
Accepted
Do EEPROMs lose their data over time?
Yes, they are based on a stupidly tiny charge on a floating gate, so eventually they will lose their memory.
The time is generally pretty long under benign conditions (seldom, if ever, re-written, ...
21
votes
Accepted
EEPROM being both "programmable" and "read-only"
Although they both involve changing the contents of memory, writing and programming are not the same thing.
Writing is done with the chip connected to the processor, during a normal processor cycle, ...
- 956
21
votes
Accepted
What is the reasoning behind parallel memory pinouts?
That is for historical reasons how these evolved and the naming conventions were just extended as memory sizes grew and needed larger packages with more pins.
First you had smaller RAMs which had less ...
- 198k
20
votes
What is the reasoning behind parallel memory pinouts?
Take a look at this diagram to see how the EPROM pin-out evolved: -
It evolved this way because that made sense (and still does). If you accept the ancient 2708's pin-out as being sensible then, ...
- 504k
18
votes
EEPROM being both "programmable" and "read-only"
Mask ROM. In Mask ROM, there is no reprogramming. Conceptually, 1's are directly connected to VCC and 0's are directly connected to ground with metalized areas in the construction of the IC. But you ...
- 29.9k
18
votes
EEPROM Fatigue - Does it affect only the cells being written excessively, or will it cause global failures?
EEPROMs don't wear out from writing, they wear out from erasing. If you look at the datasheet you'll notice that it states erase cycles.
Erase operations are block based. So an entire block of data ...
- 9,221
18
votes
2K EEPROM has only 1K?
The device is unambiguously described as a 128 x 8 "standard" EEPROM + Unique ID EEPROM.
You might accuse Microchip of being confusing, but I don't see anything resembling a lie. It's 1 ...
- 18.6k
17
votes
EEPROM being both "programmable" and "read-only"
I feel that the confusion comes from the fact that a clearly writable memory is called read-only in its name.
The resolution of the paradox: these memories contain data, which is not or just rarely ...
- 1,437
16
votes
Saving data without a microcontroller?
What you are trying to do sounds like logging.
There are lots of data loggers out there sold commercially. If you want to log voltage readings you can try googling "voltage logger". Such devices ...
- 1,690
15
votes
Best way to store very small amount of data?
Use MRAM which is basically an EEPROM of a different technology. Unlimited writes.
There is also FRAM which has nearly unlimited writes. Something on the order of a trillion writes I think. Not ...
- 58.1k
15
votes
Accepted
Use of EEPROM in automotive microcontroller when there is flash memory?
Flash is fine for memory you only need to write infrequently. It can generally only be erased in relatively large pages such as 256 bytes, not one byte or word at a time. The rated life may be only a ...
14
votes
EEPROM being both "programmable" and "read-only"
This has to do with the history of this technology: ROM (contents set in manufacturing), PROM (one time programmable), EPROM (erasable using UV light) and then EEPROM (electronically erasable) that ...
- 889
14
votes
Accepted
How Many EEPROM Write Cycles Left in My EEPROM
No, there is no way to know how many times they have been programmed. A typical user will only program them a few times, so you should be OK. If you plan on programming them tens of thousands of times,...
- 20k
14
votes
Does an EEPROM consume power only during the transition edges or during entire read/write cycle?
Here is an example write current waveform from the NXH5104 4 Mbit Serial SPI EEPROM datasheet.
In the table of 'Static characteristics' the average write supply current with 4 sectors active and 5 ...
- 57.7k
14
votes
What is the reasoning behind parallel memory pinouts?
Other answers cover the historical and upgrade-path aspects of this mapping.
But...
The exact assignment of the data and address lines to binary digits of the address doesn't matter for async SRAM at ...
13
votes
Accepted
Sequential EEPROM writing
Some sort of delay is required because the device is busy writing the data.
The datasheet for this device gives you two options to minimize it:
page writes (section 5.1.2) to write 32 bytes at a time
...
12
votes
EEPROM with high endurance
Another solution could be to use a microcontroller with non-volatile FRAM. FRAM doesn't suffer from the same limitations on write cycles as EEPROM.
Some of the MSP430 products from TI are available ...
- 25.6k
12
votes
Accepted
Does a microcontroller fetch instructions in blocks?
No and Yes.
No, because as alex.forencich points out most MCUs use NOR flash. This greatly simplifies MCU architectures, as it allows them to fetch and begin executing a single instruction at a ...
- 3,524
11
votes
EEPROM with high endurance
I have this issue in a current project.
The way I'm dealing with it is to keep the live value of the counter in RAM. I added a little bit of hardware so that the microcontroller can detect that the ...
- 317k
11
votes
Why isn't there any EEPROM in STM32F4 MCUs?
EEPROM is very expensive in terms of cell size (leading to a larger die and hence higher cost). Manufacturers started trying to get rid of EEPROM as soon as the first Flash based controllers were ...
- 1,116
10
votes
Saving data without a microcontroller?
The answer depends on your definition of "directly".
I could imagine the following setup (far from "direct", but without an MCU):
Target memory:
parallel EEPROM
ADC with an (eg.) 8-bit parallel ...
- 9,166
Only top scored, non community-wiki answers of a minimum length are eligible