SanDisk SDSDB-016G-A11 Product Manual page 12

Revision 2.2
Part No.
SDSDJ-32
SDSDB-16
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
Table 1-2
Mode
Single Block
Multiple Block
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 50-
Mb per second, and 200-Mb (25 MB) per second using four data lines.
© 2004 SanDisk Corporation
Block Data Area +
Size Protected size
(Bytes) (Blocks)
512 60,512
512 29,152
Data Transfer Formats
Single Block Mode
Memory Memory Memory
Sectors Sectors Sectors
Start Address Start Address
(Read) (Write)
Multiple Block Mode
Memory Memory Memory
Sectors Sectors Sectors
Start Address
Mode Definitions
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.
SanDisk SD Card Product Manual
Protected Area
(Blocks)
736
352
Misalignment Error
Memory Memory
Memory
Sectors Sectors
Sectors
Start Address
(Read/Write)
Memory Memory Memory
Sectors Sectors Sectors
Write Read
Stop Start
Description
1-8
Chapter 1 – Introduction
2
size User Area
(Blocks0
59,776
28,800
Memory
Sectors
Memory
Sectors
Stop
12/08/04