SD card register and function

OCR (operating conditions register): the 32-bit operating conditions register mainly stores the VDD voltage range, and the SD card operating voltage range is 2 ~ 3.6V.

CID (card identification register) register: card identification code register, 16 bytes in length, which stores the unique identification number of SD card, which cannot be modified after being programmed by the card manufacturer.

CSD (card specific data register) register: a card characteristic data register, which contains necessary configuration information for accessing the card data.

SCR (SD card configuration register): the SD card configuration register (SCR) provides some special features of the SD card. In this card, the length is 64 bits. The contents of this register are set by the manufacturer in the factory.

RCA (relative card address) register: the card relative address register is a 16 bit writable address register. The controller can select the SD card with the corresponding address through the address.

DSR (driver stage register) register: the driver stage register is an optional register used to configure the driver output of the card.

Interface controller:

It is mainly used to control and manage the internal storage core, control and set it by receiving commands sent by users, respond to commands, and then perform data reading and writing operations. Flash block for data memory storage.