MCBSTM32EXL Keil, MCBSTM32EXL Datasheet - Page 470

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

Specifications of MCBSTM32EXL

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

Secure digital input/output interface (SDIO)
20.3.2
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Table 127. Receive FIFO status flags
SDIO AHB interface
The AHB interface generates the interrupt and DMA requests, and accesses the SDIO
adapter registers and the data FIFO. It consists of a data path, register decoder, and
interrupt/DMA logic.
SDIO interrupts
The interrupt logic generates an interrupt request signal that is asserted when at least one
of the selected status flags is high. A mask register is provided to allow selection of the
conditions that will generate an interrupt. A status flag generates the interrupt request if a
corresponding mask flag is set.
SDIO/DMA interface: procedure for data transfers between the SDIO and
memory
In the example shown, the transfer is from the SDIO host controller to an MMC (512 bytes
using CMD24 (WRITE_BLOCK). The SDIO FIFO is filled by data stored in a memory using
the DMA controller.
1.
2.
3.
4.
RXFIFOF
RXFIFOE
RXFIFOHF
RXDAVL
RXOVERR
Do the card identification process
Increase the SDIO_CK frequency
Select the card by sending CMD7
Configure the DMA2 as follows:
a)
b)
c)
d)
Flag
Enable DMA2 controller and clear any pending interrupts
Program the DMA2_Channel4 source address register with the memory location’s
base address and DMA2_Channel4 destination address register with the
SDIO_FIFO register address
Program DMA2_Channel4 control register (memory increment, not peripheral
increment, peripheral and source width is word size)
Enable DMA2_Channel4
Set to high when all 32 receive FIFO words contain valid data
Set to high when the receive FIFO does not contain valid data.
used as a DMA request.
Set to high when the receive FIFO is not empty. This flag is the inverse of the
RXFIFOE flag.
Set to high when an overrun error occurs. This flag is cleared by writing to the SDIO
Clear register.
Set to high when 8 or more receive FIFO words contain valid data. This flag can be
Doc ID 13902 Rev 9
Description
RM0008