SMS512DFA5E NUMONYX, SMS512DFA5E Datasheet - Page 46

• Manufacturer Part Number: SMS512DFA5E
• Description: MICROSD CARD SMS 512MB FLASH MEM
• Manufacturer: NUMONYX

Specifications of SMS512DFA5E

• Memory Size: 512MB
• Memory Type: SD (Secure Digital)
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

Serial peripheral interface (SPI) mode
7.2.2
7.2.3
Figure 33. Read operation mechanism
Figure 34. Multiple block read operation
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Data out
Data out
Data in
Data in
Bus transfer protection
On entering the SPI mode the card defaults to the non-protected mode where there is no
CRC (Cyclic Redundancy Check). So systems using reliable data links are not obliged to
have the hardware and firmware necessary to implement CRC functions.
In non-protected mode, the CRC bits are still present but are don't care. The CRC option
can be turned on and off by the host through the CRC_ON_OFF command (CMD59).
Data read
Single and multiple block read operations are supported in SPI mode. The main difference
with the SD mode is that in SPI mode data and responses to the host are both sent on the
DataOut line. As a consequence the data transfer may be interrupted and the last data
block, replaced by the response to a STOP_TRANSMISSION command.
The basic unit of data transfer is the block. The maximum size of a block is defined in the
CSD register (READ_BL_LEN).
If READ_BL_PARTIAL is set, smaller blocks entirely contained in a physical block (as
defined by READ_BL_LEN) may also be transmitted. Single block read operations are
initiated by issuing the READ_SINGLE_BOCK command (CMD17). The start address can
be any byte in the valid address range of the card. Every block, however, must be contained
in a single physical card sector.
Multiple block read operations are initiated by issuing the READ_MULTIPLE_BLOCK
command (CMD18) and every transferred block has a 16-bit CRC appended to it. The
STOP_TRANSMISSION command (CMD12) will actually stop the data transfer operation
(just like in the SD mode).
from host
to card
from host
to card
Command
Command
Response
from card
Response
from card
to host
to host
data from card
Data block CRC
Data block CRC
to host
data from card
to host
next command
Data block CRC
STOP_TRANSMISSION
Command
next command
Data B.
command
Response
SMSxxxDF
ai10067
ai10066