Electrical Engineering Stack Exchange
Electrical Engineering Stack Exchange

Questions tagged [sd]

Secure Digital (SD), a memory card standard. Has multiple form factors (Standard, MiniSD and microSD/TransFlash) and multiple capacity ratings (SDSC, SDHC, and SDXC). Also extends to SDIO, which allows peripherals in an SD form factor to attach to a host, similar to USB.

Secure Digital (), a memory card standard. Has multiple form factors (standard, miniSD and /TransFlash) and multiple capacity ratings (SDSC, SDHC, and SDXC). Also extends to SDIO, which allows peripherals in an SD form factor to attach to a host, similar to .

microSD is a physically smaller version of the Secure Digital (SD) memory card standard. It's currently the smallest form factor in the range with dimensions of 15 × 11 x 1 mm. Electronically, it is identical to full-sized SD cards and MiniSD cards.

MMC cards are similar, and pin compatible, though the protocol is different. SD competed with CompactFlash cards, though it has widely won out as the go to flash card standard.

Further reading:

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Is it true that a SD/MMC Card does wear levelling with its own controller?

I can't find any reliable information about this. I don't have the full specification of the SD/MMC Card hardware. Is it true? My high-level application doesn't need to be concerned with wear leveling when working with these cards? EDIT Could…
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MicroSD card performance deteriorates after long-term read-only usage

I'm using a STM32L432 microcontroller to read data from a microSD card via SPI. In my application, I'm playing a sound file with a length of 10 s in loop. I found out that after the application ran for approximately 20 - 25 hours, the audio stream…
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Do I need to pay royalties to the SD card people if my device "just happens" to be compatible with SD cards?

I'm designing something which will use an SD card. The device will be able to read and write the cards, using publicly available specifications. Do I need to pay the SD card people?
Thomas O
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Do all microSD cards support SPI mode?

Have you ever encountered an SD card which does not support the SPI mode? I read microSD are not required to but I believe all do support SPI. EDIT: The information about optionality of SPI seems to come from Wikipedia and was recently removed (here…
jpc
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How do I protect SD card against unexpected power failures?

I am working on a device that uses the Microchip MDDFS library to store data to an SD card. The logger will log data at a maximum rate of 1 entry (56bytes) every minute. The problem is the device may lose power at any time, potentially in the middle…
PICyourBrain
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Why is SPI Flash memory so limited in max size, and cost way more (per MB) than SD flash memory?

For example: SPI Flash largest size is 512MB at $9/ea: SPI Flash prices vs 2GB of microSD $3/ea (some with $1 shipping): microSD prices
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How can I initialize/use SD cards with SPI?

I've seen various blog and forum posts, tutorials and application notes about accessing SD cards with microcontrollers using SPI, but I struggled a lot at different points when following them. In my following answer, I tried to sum up an…
Matthias Luh
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How can V-USB screw up the built-in SPI of an ATmega328p?

I'm working on a V-USB project that shows up as a Keyboard using an ATmega328p. The USB part is working great (it's not my first V-USB project), but after I start the V-USB stack with usbInit(), all calls to the SD card library fail. If I call the…
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How to make 1 bit permanent memory circuit?

I would like to make a simple circuit to store or save 1 bit of data. The circuit should be able to remember the state of an LED ( on or off ) even if the supply is disconnected from the circuit. I need it to work like a hard drive, flash memory or…
Michael George
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Saving data to an SD card memory module using an Arduino

Is it possible to save data from the Arduino to an SD card memory module?
desNotes
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Difference between 1-bit, 4-bit and 8-bit SDIO

Please help me understand the significance of 8-bit SDIO over 1-bit and 4-bit SDIO. Let me know the pros and cons of each type. Wiki or SDIO specification document does not discuss this.
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Why is data stored on a NAND chip irretrievable if cracked?

All data recovery companies, regardless of skill, unanimously say that if the memory chip of a device has just a hair line crack, data recovery is impossible. Not unlikely, not expensive, but impossible. One company even stated that even the FBI…
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Does magnetism affect SD cards?

Would a strong magnet have any effect whatsoever on a thumb drive (I'm assuming not) or on an SD card? It seems unlikely, but I'm hoping someone can give me a definitive answer, since I'd rather not find out the hard way that it actually can. …
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Are there problems accessing a microSD card via SPI when there are other slave SPI devices?

I'm working on a design that has a CPU with only one SPI port. I have multiple (3) slaves connected to this port, one of which is a microSD card. Here is a report from an engineer who says that SD cards are designed to operate as the only slave to…
jpeskin
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Anyone either read japanese or know about laying tracks for a micro SD card slot?

I'm trying to include a micro SD card slot in a project I'm working on and I'm having a little trouble with the datasheet. Unfortunately I don't read japanese. Just wondering what the text says in the 3 Shaded boxes on page…
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