FX3S/SD3板上的SD端口电源域如何切换FX3S中的I/O电压？

是的，UHS-I SD存储卡在初始化时使用3.3V的信号电压，然后移动到1.8V。
它如何切换I/O电压？
我们需要一个外部稳压器，将电压从3.3 V移到1.8 V。这个移位将由在ItfPARAMS中提供的GPIO控制。
首先，我们必须设置接口的参数，这样端口支持低电压操作。这可以通过传递到IpfPARAM.低压的Cyror来完成。如果是真的，接下来提供可用于控制调节器的GPIO。这应该在应用固件中完成。
你必须把配置好的GPIO连接到调节器。
查找卡规范并声明GPIO（如果需要的话）在库中处理。
在带有App Note AN89661的USB RAID 1示例项目中，我们已经配置了端口0参数如下：
EnfPARAM.RESETGPIO＝0xFF；/*没有SDI/MMC功率的GPIO控制。*/
ItfPARAMS.rStasthy= CyTrime；/*不在乎没有选择GPIO。*/
ItfPARAMS.CARDDETYTYPE＝CyuU3PySbIdExtExtDATE3；/*卡检测基于SDGDAT（3）。*/
ItfPARAMS.WrrePrtuabely= CyTrime//*写保护处理启用。*/
低电压= CyTrime//*低电压操作启用。*/
在S0端口上电压开关使用GPIOE12，*/VasigsWGPIO/VSELYS0SGPIO；/*使用GPIOE12。
启用了CyTrime//DDR时钟。*/
nfFiqq＝CyuU3psibFRYQ1010MHz；/*无S端口时钟限制。*/
卡秒延迟＝5；/* SD卡插入之间不需要延迟
初始化之前。*/
状态= CYU3PSIBSETIN FPARAMS（0，＆；
参考附图FX3S RAID芯片上的USB软件包，我们已经连接了VSELYVIO2（GPIO 12）到第6页的调节器U1。当您插入UHS- I卡时，此GPIO将触发。
FX3S——USB RAID芯片USB DeNE.PDF的原理图
221.2 K



     以下为原文
  Yes, the UHS-I SD memory card uses 3.3V signal voltage at initialization and then shifts to 1.8V.
 
How does it switch the I/O voltage?
We need an external regulator which shifts the voltage from 3.3 V to 1.8 V. This shifting will be controlled by the GPIO provided in the intfparams.
First, We have to set the parameters of the interface in such away that port supports the lowvoltage operation. This can be done by passing CyTrue to intfParams.lowVoltage. If it is true, next provide the GPIO which can be used for controlling the regulator. This should done in the application firmware.
And you have to connect the configured GPIO to regulator.
 
Looking for the card specification and asserting the GPIO, if required, is handled in the library.
 
In USB RAID 1 example project provided with the App Note AN89661, we have configured the port 0 parameters as follows:
intfParams.resetGpio      = 0xFF;                   /* No GPIO control on SD/MMC power. */
intfParams.rstActHigh      = CyTrue;                /* Don't care as no GPIO is selected. */
intfParams.cardDetType    = CY_U3P_SIB_DETECT_DAT_3;/* Card detect based on SD_DAT[3]. */
intfParams.writeProtEnable = CyTrue;                /* Write protect handling enabled. */
intfParams.lowVoltage      = CyTrue;       /* Low voltage operation enabled.*/
intfParams.voltageSwGpio  = VSEL_S0_GPIO;  /* Use GPIO_12 for voltage switch on S0 port.*/
intfParams.useDdr          = CyTrue;                 /* DDR clocking enabled. */
intfParams.maxFreq        = CY_U3P_SIB_FREQ_104MHZ;   /* No S port clock limitation. */
intfParams.cardInitDelay  = 5;                         /* No delay required between SD card insertion
                                                                  before initialization. */
status = CyU3PSibSetIntfParams (0, &intfParams);
 
Refer the attached Schematic of FX3S RAID-ON-CHIP USB DONGLE, we have connected the VSEL_VIO2 (GPIO 12) to regulator U1 in page 6. This GPIO will triggered when you insert the UHS-I card.
    

•   FX3S- Schematic of USB RAID ON CHIP USB DONGLE.pdf 221.2 K