ST STM32L4+ Series Reference Manual page 2001

RM0432
SDMMC_CK
SDMMC_D2
SDMMC_D3
SDMMC_D1
SDMMC_D0
In ReadWait SDMMC_D2 signaling, when RWSTART is set, the DPSM drives SDMMC_D2
after the End bit of the current received data block CRC. The ReadWait signaling on
SDMMC_D2 will be removed when writing 1 to the RWSTOP bit. The DPSM remains in
ReadWait state for two more SDMMC_CK clock cycles to drive SDMMC_D2 to 1 for one
clock cycle (in accordance with SDIO specification), where after the DPSM waits for a Start
bit from the card.
During the ReadWait signaling on SDMMC_D2 commands can be issued to the card.
During the ReadWait interval, the SDMMC can detect SDIO interrupts on SDMMC_D1.
54.6.2 CMD12 send timing
CMD12 is used to stop/abort the data transfer, the card data transmission is terminated two
clock cycles after the End bit of the Stop Transmission command.
Data operation
SDMMC stream write
SDMMC open ended
multiple block write
SDMMC block write with
predefined block count
SDMMC stream read
Secure digital input/output MultiMediaCard interface (SDMMC)
Figure 591. ReadWait with SDMMC_CK > 50 MHz
t
OP
0 1 2 3 4 5
1
Read data
End
1
Read data
End
2 CK min.
5 CK max.
Table 404. CMD12 use cases
Stop Transmission command CMD12 Description
The data transfer is stopped/aborted by sending the Stop Transmission
command.
The data transfer is stopped/aborted by sending the Stop Transmission
command.
If the card detects an error, the host must abort the operation by sending
the Stop Transmission command.
The Stop Transmission command is not required at the end of this type of
multiple block write. (sending the Stop Transmission command after the
card has received the last block is regarded as an illegal command.)
If the card detects an error, the host must abort the operation by sending
the Stop Transmission command.
The data transfer is stopped/aborted by sending the Stop Transmission
command.
RM0432 Rev 6
N 8 CK min.
AC
6 7 8 8 8
Read wait
t
OP
8 9 10
0
Read data
Start
0
Read data
Start
2001/2301
MSv40948V2
2041