Chapter 5 – SPI Protocol
Revision 2.2 SD Card Product Manual
© 2004 SanDisk Corporation 5-14 12/08/04
5.18.4 Format R3
The SD Card sends this response token when an READ_OCR command is received. The
response length is five bytes. The structure of the first (MSB) byte is identical to response
type R1. The other four bytes contain the OCR Register.
Figure 5-9 R3 Response Format
5.18.5 Formats R4 and R5
These response formats are reserved for I/O mode (refer to SDIO Card Specification).
5.18.6 Data Response
Every data block written to the card is acknowledged by a data response token. It is one-
byte long and has the following format:
The meaning of the status bits is defined as follows:
‘010’—Data accepted.
‘101’—Data rejected due to a CRC error.
‘110’—Data rejected due to a Write Error
In case of any error (CRC or Write) during Write Multiple Block operation, the host will
stop the data transmission using CMD12. In case of Write Error (response ’110’) the host
may send CMD13 (SEND_STATUS) in order to get the cause of the write problem.
ACMD22 can be used to find the number of well-written write blocks.
5.19 Data Tokens
Read and write commands have data transfers associated with them; data is transmitted or
received via data tokens. All data bytes are transmitted MSB.
Data tokens are 4 to 515 bytes long and have the following format:
Single-Block Read, Single-Block Write and Multiple-Block Read:
• First byte: Start Block.
• Bytes 2-513 (depends on the data block length): User Data.
• Last two bytes: 16-bit CRC.
39
0
32 31 0
R1 OCR
7
x x x 0
0
Status 1
6
7
1
0
01 1 1 1 1 1
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