Negotiating Operating Conditions; Card Acquisition And Identification; Card Status; Memory Array Partitioning - SanDisk SDSDB-32-201-80 - Industrial Grade Flash Memory Card Product Manual

Introduction to the SD Card

1.5.10.1. Negotiating Operating Conditions

The operating condition negotiation function of the SD Card bus is supported differently in SPI mode by using the
READ_OCR (CMD58) command. The host shall work within the valid voltage range (2.7 to 3.6 volts) of the card
or put the card in inactive state by sending a GO_INACTIVE command to the card.

1.5.10.2. Card Acquisition and Identification

The host must know the number of cards currently connected on the bus. Specific card selection is done via the CS
signal (CD/DAT3). The internal pullup resistor on the CD/DAT3 line may be used for card detection
(insertion/removal). Additional practical card detection methods can be found in SD Physical Specification's
Application Notes given by the SDA.

1.5.10.3. Card Status

In SPI mode, only 16 bits (containing the errors relevant to SPI mode) can be read out of the 32-bit SD Card status
register. The SD_STATUS can be read using ACMD13, the same as in SD Bus mode.

1.5.10.4. Memory Array Partitioning

Memory partitioning in SPI mode is equivalent to SD Bus mode. All read and write commands are byte addressable
with the limitations given in Section 1.5.9.5.

1.5.10.5. Read and Write Operations

In SPI mode, both single and multiple block data transfer modes are supported.

1.5.10.6. Data Transfer Rate

In the SPI mode, only one data line is used for each direction. The SPI mode data transfer rate is the same as the SD
Bus mode data transfer rate when using one data line only (up to 25 Kbits per second).

1.5.10.7. Data Protection in the SD Card

Same as for the SD Card mode.

1.5.10.8. Erase

Same as in SD Card mode.
SanDisk Secure Digital (SD) Card Product Manual, Rev. 1.9 © 2003 SANDISK CORPORATION 1-11