GD32F403xx User Manual
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Figure 20-5. SDIO sequential write operation
20.4.
SDIO functional description
The following figure shows the SDIO structure. There have two main parts:
◼
The SDIO adapter block consists of control unit which manage clock, command unit
which manage command transfer, data unit which manage data transfer.
◼
The AHB interface block contains access registers by AHB bus, contains FIFO unit which
is data FIFO used for data transfer, and generates interrupt and DMA request signals.
Figure 20-6. SDIO block diagram
SDIO controller
HCLK
SDIO CLK
SDIO_CMD
SDIO_CLK
SDIO_DAT[7:0]
SDIO adapter
control unit
comm and
unit
data uni t
regi sters
FIFO
AHB interface
interrupt
DMA r equest
AHB bus
20.4.1.
SDIO adapter
The SDIO adapter contains control unit, command unit and data unit, and generates signals
to cards. The signals is descript bellow:
SDIO_CLK
: The SDIO_CLK is the clock provided to the card. Each cycle of this signal directs