Questions tagged [sdio]
Secure Digital Input Output extends the SD card specification to cover input/output functions.
34 questions
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PCB layout guidelines for SDIO at 25MHz
I am currently using a WeAct Studio STM32H562RGT6 development board, and everything is working fine except 4-bit SDIO, which is unreliable if I use a clock divider less than 20 (~2MHz). Ideally I ...
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Multiple devices on SDIO bus
We are developing a board for a SoM with an Altera Cyclone V FPGA SoC. The OS is a custom embedded Linux created with Buildroot.
We need an SD card, Bluetooth, and Wi-Fi. For this, we have identified ...
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Is this SD card interface circuit with ESD protection and PMOS power switch correctly designed?
I'm designing an SD card interface for a 3.3V system and would appreciate a review of the schematic I've put together. The goal is to safely interface with a microSD card in 4-bit mode, provide robust ...
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stm32h7 sdmmc DATA problem
Im trying to send data with sdmmc and i cant see anything happening in data line on oscio.
CMD and CLOCK working fine but data just doesnt reacting.
this is how clock and cmd looking like (no data ...
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Issue in USB_OTG_FS and SD card Integration
I am currently working on a project that involves integrating USB functionality for data transfer and data logging on an STM32F407VG micro-controller. Specifically, I want to log data files on an SD ...
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SD Card with SDIO Interface Issues on STM32F446RET6 PCB
We are currently working on a PCB that has an STM32F446RET6 MCU. The PCB is equipped with various sensors for data collection. Additionally, we are using an SD card for data logging and have opted for ...
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SD Card CLK stops working properly on STM32F4 with SDIO connections
I have an SD Card socket connected to STM32F4 with the connections as follows:
The firmware uses the following codes to initialize the SDIO:
...
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Why application notes advise series resistance to be added on clock lines for high-speed interfaces, like SDIO, and not on data lines?
Many application notes (like this one) advise series resistance to be added on the clock line, close to the source. I do understand that this resistance is added there to match the source impedance to ...
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How do I communicate with the Wifi module on an stm32mp157f-dk2 board in bare metal?
I'm trying to establish communication with the WiFi module on an stm32mp157f-dk2 board.
I must be doing something wrong because I always get a timeout from SDMMC2.
I attempt to send 2 commands, the ...
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Sequential writing from different hosts to one SD/SDIO
I was wondering if it is possible to access one SD card via two or more hosts via some sort of hub and write to it data sequentially (i.e host1 writes a bulk then hostN writes another bulk)
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WL1837MOD SDIO Control(or Wifi module in general)
There are a number of wifi module which are controlled by SDIO(as an option). I am using the WL1837MOD as a specific example but I welcome more general answers.
All the documentation for this chip ...
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Do SDIO bus speeds need to match between two devices?
I have two devices that I'd like to use together, connected via their SDIO pins. The MCU can transfer data up to 200 MB/s with a 200 MHz clock speed (HS-200). The wireless module that I want to use ...
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microSD card communication problem
I am developing an embedded system and attaching a uSD-card to it in SD mode (not SPI). The requirement is such that I have to switch the uSD card connectivity between two ports so I am using 74HC4053 ...
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Clock line of SDIO bus has worse rise/fall time than rest of bus
I have an ATWILC3000 wifi module connected to a Raspberry Pi Compute Module 3+ over 4-bit SDIO. It's throwing a lot of bus errors at higher frequencies (currently running at 1 MHz for stability when ...
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STM32 SDIO works only while probing clock signal
I have a custom board with an STM32F407VGT6 and an SD card slot. I noticed that I can only access the SD card if I have a scope probe attached to the clock signal. Holding a scalpel blade between my ...
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