Datasheet

Table Of Contents
Bit 6 – EXTUN Execute Tuning
This bit is set to 1 to start the tuning procedure and is automatically cleared when the tuning procedure is
completed. The result of tuning is indicated to Sampling Clock Select (SCLKSEL). The tuning procedure
is aborted by writing 0. Refer to Figure 2.29 in the “SD Host Controller Simplified Specification V3.00” .
Value Description
0
Not tuned or tuning completed
1
Execute tuning
Bits 5:4 – DRVSEL[1:0] Driver Strength Select
The peripheral output driver in 1.8V signaling is selected by this bit. In 3.3V signaling, this field is not
effective. This field can be set according to the Driver Type A, C and D support bits in CA1R.
This field depends on setting of Preset Value Enable (PVALEN):
PVALEN=0 - This field is set by the user.
PVALEN=1 - This field is automatically set by a value specified in one of the PVRx.
Value Name Description
0
TYPEB Driver Type B is selected (Default)
1
TYPEA Driver Type A is selected
2
TYPEC Driver Type C is selected
3
TYPED Driver Type D is selected
Bits 3:0 – HS200EN[3:0] HS200 Mode Enable
This field is used to select the e.MMC HS200 mode. When HS200EN is set to B
(hexa)
, the HS200 mode is
enabled. Any other value except 0 is forbidden when interfacing an e.MMC device.
If Preset Value Enable is set to 1, peripheral sets SDCLK Frequency Select (SDCLKFSEL), Clock
Generator Select (CLKGSEL) in CCR and Driver Strength Select (DRVSEL) according to PVR. In this
case, one of the preset value registers is selected by this field. The user needs to reset SD Clock Enable
(SDCLKEN) before changing this field to avoid generating a clock glitch. After setting this field, the user
sets SDCLKEN to 1 again.
Note:  This field is effective only if MC1R.DDR is written to 0.
SAM D5x/E5x Family Data Sheet
SD/MMC Host Controller ...
© 2019 Microchip Technology Inc.
Datasheet
DS60001507E-page 1366