Specifications

Physical Layer Simplified Specification Version 4.10

3.9 Ultra High Speed Phase I (UHS-I) Card

UHS-I provides up to 104MB/sec performance on 4-bit SD bus with the single end driver interface. Card

form factor is the same and existing connector can be used.

3.9.1 UHS-I Card Operation Modes

• DS - Default Speed up to 25MHz 3.3V signaling

• HS - High Speed up to 50MHz 3.3V signaling

• SDR12 - SDR up to 25MHz 1.8V signaling

• SDR25 - SDR up to 50MHz 1.8V signaling

• SDR50 - SDR up to 100MHz 1.8V signaling

• SDR104 - SDR up to 208MHz 1.8V signaling

• DDR50 - DDR up to 50MHz 1.8V signaling

Note: 1.8V signal timings are different from those of 3.3V.

3.9.2 UHS-I Card Types

UHS-I supports two card Types:

• UHS50

• UHS104

UHS-I is not applied to SDSC card but can be applied to SDHC and SDXC card.

Figure 3-14 and Figure 3-15 show UHS-I supported modes.

DDR50 is mandatory for microSD form factor and optional for Standard size SD form factor

Figure 3-14 : UHS-I Card Type Modes of Operation versus Frequency Range

SDR

50 3.3V

1.8V

Signal Voltage

SDR12

SDR25

25MHz 50MHz 100MHz 208MHz

UHS50

Card

DS: Default Speed Mode

HS: High Speed Mode

SDR

SDR12

SDR25

UHS104 Card

SDR104

DDR50

Frequency