We are designing a SD card interface with a processor.The processor supports SDR104 with clock frequency of 192MHz. Along similar lines,the UHS modes and corresponding clock frequencies mentioned are, SDR25 - 48 MHz ; SDR50 - 96 MHz ; DDR50 - 48 MHz ;
Don't we need at-least 208 MHz clock frequency to transfer 4 bit of data in SDR104 Mode(at 104MB/s) or about 50 and 100 MHz for SDR25/DDR50 and SDR50 modes? If the maximum achievable clock frequency is 192 MHz,are we still operating in SDR104 mode?
Please help me to understand these data rates and clock frequencies.