MMC/SD Host Controller
7-123
MPU Public Peripherals
Table 7–91. MMC/SD Signal Pads
Pad Name
Type
Pullup/
Pulldown
Reset
Value
Description
MMC.CLK
Out
-
0
MMC/SD card CLK signal.
Only active during active command to a MMC/SD card
using MMC or SPI protocols.
MMC.CMD_SPI.
DO/SPI_SO
In-Out
Pullup
(*3)
Input
MMC/SD card CMD signal in MMC/SD mode.
SPI serial out signal in SPI mode (output—goes to serial
In of target device(s)).
MMC.DAT[0]
/SPI_SI
In-Out
Pullup
(*3)
Input
MMC card DAT or SD card DAT[0] signal in MMC/SD
mode.
SPI serial in signal in SPI mode (input—comes from serial
out of target device(s)).
MMC.DAT[3-1]
(*1)
In-Out
Pullup
(*3)
Input
SD card DAT[3-1] signals in MMC/SD mode.
Reserved signals for MMC card or in SPI mode.
GPIO2
(SPI.CLK)
(*2)
In- Out
(Out)
Pulldown
(disabled)
Input
(0)
By default, pad used by the GPIO2. The SPI_CLK output
signal can be multiplexed.
SPI_CLK only active during SPI transfers to serial flash or
other SPI devices (except MMC/SD cards).
GPIO3
(SPI.C/Sn[3])
(*2)
In-Out
(Out)
Pulldown
(disabled)
Input
(1)
By default, pad used by the GPIO3. The SPI CSn(3)
output signal can be multiplexed. SPI CSn(3) is active
low, only active in SPI mode during SPI transfers.
Reserved in MMC/SD mode.
GPIO4
(SPI.C/Sn[2])
(*2)
In-Out
(Out)
Pulldown
(disabled)
Input
(1)
By default, pad used by the GPIO4. The SPI CSn(2)
output signal can be multiplexed. SPI CSn(2) is active
low, only active in SPI mode during SPI transfers.
Reserved in MMC/SD mode.
GPIO6
(SPI.C/Sn[1])
(*2)
In-Out
(Out)
Pulldown
(disabled)
Input
(1)
By default, pad used by the GPIO6. The SPI CSn(1)
output signal can be multiplexed. SPI CSn(1) is active
low, only active in SPI mode during SPI transfers.
Reserved in MMC/SD mode.
GPIO0
(SPI.RDY)
(*2)
In-Out
(In)
Pulldown
(disabled)
Input
(Input)
By default, pad used by the GPIO0. The SPI ready/busy
input can be multiplexed. When SPI_RDY is low, it
denotes busy condition. Only active in SPI mode during
SPI transfers. Reserved signal in MMC/SD mode
Notes:
1) Optional signals. Only needed for SD cards.
2) Optional signals. Only needed for devices with SPI interfaces (serial flash, etc.).
3) This pullup is enabled/disabled dynamically by the MMC/SD host controller.