Delkin Blog

SD Card Pinout Basics

 

The serial interface of SD cards has made them hugely popular in both consumer and industrial devices for OEMs. The SD Card Association tightly controls the specifications of SD cards, including the SD card pinout, so there are universal standards for everything from physical interfaces to command protocols that make integration seamless and easy. SD cards are designed to meet the needs of both consumer and industrial markets and their differing budgets. Most consumer devices rely on MLC flash memory, while industrial devices use SLC flash.  An SD card pinout can vary depending on the mode of the card.

 

SD Card Modes

SD cards automatically use SD mode for the bus protocol. SD mode offers high speeds and bus widths of between one and four bits in clock serial mode. Users can override the SD mode default, however, to use the card in SPI mode. SPI mode is best suited for applications in which a slower, simpler card is ideal. The speed difference with SD and SPI modes can be significant, as the card can only operate at one bit in SPI mode.

 

SD Card Pinouts in SD Mode

Each SD card, regardless of mode, has 9 pins, with the eighth pin at one end and the ninth at the other. When running in SD mode, the pinout and signal functions look like this:

 

  1. DAT1 – Data bit one
  2. DATA0/DO – Data bit 0
  3. Vss2 – Ground 2
  4. CLK – Clock
  5. Vcc – Supply voltage
  6. Vss1 – Ground 1
  7. CMD/DI – Command line
  8. DAT3/CS – Data bit 3
  9. DAT2 – Data bit 2

 

With this pinout, SD cards can support normal and high speed modes.

 

SD Card Pinouts in SPI Mode

SPI mode offers simpler functioning, and not every pin has a connection. The pinout and the signal functions are as follows:

 

  1. RSV – Reserved
  2. DO – Master In/Slave Out (or MISO)
  3. Vss – Ground
  4. CLK – Clock
  5. Vcc – Supply voltage
  6. DI – Master Out/Slave In (MOSI)
  7. CS – Chip Select
  8. NC – No connection
  9. RSV – Reserved

 

Do you have questions about SD card pinouts and using SD cards for flash storage? Delkin is here to provide the information you need and help you evaluate all of your options for industrial-grade, rugged memory. Talk to our product team today.

 

Contact

  • This field is for validation purposes and should be left unchanged.

 

 

Related Posts

Temperature Considerations for SSD- Hot Climate
The Benefits of Industrial Temperature for Industrial Applications

  Flash storage solutions come in two categories—commercial and industrial. These two product grades are...

Digital Gaming Applications
Industrial CompactFlash (CF) Cards: The Perfect Fit for Gaming Applications

  Behind the bright lights and ringing sounds of casinos are the flash storage cards...

A Case Study in Application Design That Considers Technological Advancements

  When designing state-of-the-art technological applications, designers and engineers are faced with a major challenge—creating...

Healthcare Industrial Flash Storage
Modernize Your Healthcare Data Storage with Industrial Flash

  The healthcare community relies heavily on tech for daily functions, from reading test results...

Delkin Industrial Application Lifecycle Management
Product Life Cycle Management FAQs

  When it comes to flash storage, developing a world-class application isn’t enough. Life cycle...

Person on laptop evaluating SMART data
Customer Success Story: Enhance Embedded Memory with SMART Cards

Flash storage offers a modernized opportunity to store and access data at a high...

Ruggedized SSDs- Technology for Industrial Users: What You Need to Know

  SSDs are so ubiquitous today that you may be surprised to learn that they...

Delkin Devices Technical Support: We’re Here to Help

  Delkin Devices is a global industrial Flash memory and storage provider with the best...

Power Fail
Understanding Power Failures in Flash Storage

  The Cost of Power Failures  For industrial applications, the cost of power failures can be...

Ruggedized SSDs- Technology for Industrial Users: What You Need to Know

  SSDs are so ubiquitous today that you may be surprised to learn that they...