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That is to provide a way to turn on / off the power supply to the SD card if required. However the default firmware doesn't seem to use GPIO 14 for this purpose. But this can be included if required.
- Madhu Sudhan
Hi Madhu Lakshmipathy,
i am interfacing sd card to fx3s,sd card type is SDXC UHS-1,
For sdxc card detection,UHS-I SD memory card uses 3.3V signal voltage at initialization and then shifts to 1.8V. As suggested in FX3S- Schematic of USB RAID ON CHIP USB DONGLE , we connected an external regulator and monitoring this using GPIO.
according to AN70707,
1)In the case of SD card, the VDD should be tied to 3.3 V regardless of the I/O voltage used on the other SD lines.
2)SD card voltage supply (VIO2 or VIO3) should be changed to 1.8 V dynamically when UHS-I memory card is used.
various operating frequencies supported on the storage port by the FX3S device
* CY_U3P_SIB_FREQ_104MHZ (intfParams.maxFreq = CY_U3P_SIB_FREQ_104MHZ)
my questions are
1)Is there any relation between operating frequency on storage port and its io voltage??
2)if io voltage of s port is 3.3v and suplly voltage vdd is 3.3v, storage port will detect sdxc interface??
3)if operating frequency is 48MHz,do we need an external regulator to switch the voltage from 3.3v to 1.8v?
4)if frequency is greater than 48MHz,do we need an external regulator?
5)what is 48MHz will do?is it only for read from and write to sd card data speed?
please let me know,help us