MCBSTM32EXL Keil, MCBSTM32EXL Datasheet - Page 457

• Manufacturer Part Number: MCBSTM32EXL
• Description: BOARD EVALUATION FOR STM32F103ZE
• Manufacturer: Keil

Specifications of MCBSTM32EXL

• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

RM0008
20.2
The MultiMediaCard/SD bus connects cards to the controller.
The current version of the SDIO supports only one SD/SDIO/MMC4.2 card at any one time
and a stack of MMC4.1 or previous.
SDIO bus topology
Communication over the bus is based on command and data transfers.
The basic transaction on the MultiMediaCard/SD/SD I/O bus is the command/response
transaction. These types of bus transaction transfer their information directly within the
command or response structure. In addition, some operations have a data token.
Data transfers to/from SD/SDIO memory cards are done in data blocks. Data transfers
to/from MMC are done data blocks or streams. Data transfers to/from the CE-ATA Devices
are done in data blocks.
Figure 177. SDIO “no response” and “no data” operations
Figure 178. SDIO (multiple) block read operation
SDIO_CMD
SDIO_D
From host to card From card to host
SDIO_CMD
Command
SDIO_D
Block read operation
From host to card(s)
Response
Command
Data block crc
Operation (no response)
Multiple block read operation
Doc ID 13902 Rev 9
data from card to host
Data block crc
Secure digital input/output interface (SDIO)
From host to card
Command
Operation (no data)
Data block crc
From card to host
Command
Data stop operation
Response
Stop command
stops data transfer
Response
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