Sdio Adapter; Table 128. Sdio I/O Definitions; Figure 314. Sdio Adapter - ST STM32F40 Series Reference Manual

RM0090

Table 128. SDIO I/O definitions

Pin
SDIO_CK
SDIO_CMD
SDIO_D[7:0]
28.3.1

SDIO adapter

Figure 314

Figure 314. SDIO adapter

To APB2
interface
The SDIO adapter is a multimedia/secure digital memory card bus master that provides an
interface to a multimedia card stack or to a secure digital memory card. It consists of five
subunits:
●
Adapter register block
●
Control unit
●
Command path
●
Data path
●
Data FIFO
Note: The adapter registers and FIFO use the APB2 bus clock domain (PCLK2). The control unit,
command path and data path use the SDIO adapter clock domain (SDIOCLK).
Adapter register block
The adapter register block contains all system registers. This block also generates the
signals that clear the static flags in the multimedia card. The clear signals are generated
when 1 is written into the corresponding bit location in the SDIO Clear register.
Direction
MultiMediaCard/SD/SDIO card clock. This pin is the clock from
Output
host to card.
MultiMediaCard/SD/SDIO card command. This pin is the
Bidirectional
bidirectional command/response signal.
MultiMediaCard/SD/SDIO card data. These pins are the
Bidirectional
bidirectional databus.
shows a simplified block diagram of an SDIO adapter.
SDIO adapter
Adapter
registers
FIFO
PCLK2
Doc ID 018909 Rev 4
Secure digital input/output interface (SDIO)
Description
Control unit
Command
path
Data path
SDIOCLK
SDIO_CK
SDIO_CMD
SDIO_D[7:0]
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