SanDisk SDSDB-016G-A11 Product Manual - Page 12

Revision 2.2 Chapter 1 - Introduction SanDisk SD Card Product Manual Part No. SDSDJ-32 SDSDB-16 Block Size (Bytes) 512 512 Data Area + Protected size (Blocks) 60,512 29,152 Protected Area2 size (Blocks) 736 352 User Area (Blocks0 59,776 28,800 1.12.6 Read/Write Operations The SD Card supports two read/write modes as shown in Figure 1-3 and defined in Table 1-2. Figure 1-3 Data Transfer Formats Single Block Mode Memory Sectors Memory Memory Sectors Sectors Memory Sectors Misalignment Error Memory Sectors Memory Sectors Memory Sectors Start Address (Read) Start Address (Write) Start Address (Read/Write) Multiple Block Mode Memory Sectors Memory Sectors Memory Sectors Memory Sectors Memory Memory Sectors Sectors Memory Sectors Write Read Start Address Stop Start Stop Table 1-2 Mode Single Block Multiple Block Mode Definitions Description In this mode the host reads or writes one data block in a pre-specified length. The data block transmission is protected with 16-bit CRC that is generated by the sending unit and checked by the receiving unit. The block length for read operations is limited by the device sector size (512 bytes) but can be as small as a single byte. Misalignment is not allowed. Every data block must be contained in a single physical sector. The block length for write operations must be identical to the sector size and the start address aligned to a sector boundary. This mode is similar to the single block mode, except for the host can read/write multiple data blocks (all have the same length) that are stored or retrieved from contiguous memory addresses starting at the address specified in the command. The operation is terminated with a stop transmission command. Misalignment and block length restrictions apply to multiple blocks and are identical to the single block read/write operations. 1.12.7 Data Transfer Rate The SD Card can be operated using either a single data line (DAT0) or four data lines (DAT0-DAT3) for data transfer. The maximum data transfer rate for a single data line is 50Mb per second, and 200-Mb (25 MB) per second using four data lines. © 2004 SanDisk Corporation 1-8 12/08/04