SD Specifications Part 1 UHS-II Simplified Addendum - SD Association

UHS-II Simplified Addendum Version 1.01©Copyright 2010-2013 SD Card AssociationIf Host intends to use UHS-II interface, it supplies VDD2, RCLK and VDD1 after power up, and setsSTB.L on D0.Tx. Device connects termination resistors of RCLK Lanes after power up. Device startsPHY Initialization when receiving STB.L and responds STB.L if it succeeds.The method for Host to distinguish whether Device fails to start PHY initialization is through detectingtimeout from Host's setting STB.L on D0.Tx to receiving it on D1.Rx, which can be estimated fromTeidl_stb and UHS-II bus topology.If Host detects timeout, Host sets RCLK Lane to DIF-Z to stop supplying RCLK, and then Host suppliesSDCLK and issues CMD8 and ACMD41 for Legacy SD protocol to initialize SD interface. Then, Hostproceeds card identification and the card status transits to "data transfer mode" in Legacy SD (same asdata transfer mode defined in SD Specifications Part 1 Physical Layer Simplified Specification Version4.10) as a result. When Legacy SD interface is selected, UHS-II interface that is activated by power upis disabled before ACMD41 is completed. Moreover, termination resistors of RCLK Lanes in Device aredisconnected when disabling UHS-II interface. As the sequence to "data transfer mode" in Legacy SD inFigure 7-11 is simplified, refer to SD Specifications Part 1 Physical Layer Simplified SpecificationVersion 4.10 for detailed specifications of Legacy SD initialization. Note that if CMD0 is issued inLegacy SD card state transits to 'idle'. (Note that it is impossible to execute (UHS-II) PHY Initialization.)On the other hand, if Device succeeds PHY Initialization, UHS-II interface is available and then, DeviceInitialization, Enumeration and Configuration take place in this order. If Host detects "Application Type"is "SD memory" or "SDIO" during Configuration, it can issue the encapsulated SD CMD. Host shallexecute card identification described in Section 7.2.4.1 by encapsulated SD CMDs in case of detecting"SD memory". If encapsulated CMD0 is issued, card state transits to 'idle' in SD-TRAN. On the otherhand, if FULL_RESET CCMD is issued, Device waits STB.L for PHY Initialization.If Host intends to use only Legacy SD interface or detects that Legacy SD Card is inserted, it is allowedto supply only VDD1 and SDCLK, and issue CMD8 in order to accelerate initialization of Legacy SDinterface. Note that once UHS-II I/F is disabled, Host requires power cycle to enable UHS-II again.Refer to Section 3.10.4 in SD Specification Part 1 Version 4.00 for more details about VDD2 supply.Note that Device's power consumption during Device Initialization is not regulated by Power Limitspecified by CMD6, but parameters specified by DEVICE_INIT CCMD.7.2.3.3 Interface Selection after FULL_RESET or GO_DORMANT_STATEFigure 7-12 shows a concept diagram of initialization flow after executing FULL_RESET orGO_DORMANT_STATE CCMD.84