NAND08GAH0A NUMONYX [Numonyx B.V], NAND08GAH0A Datasheet - Page 33

• Manufacturer Part Number: NAND08GAH0A
• Manufacturer: NUMONYX [Numonyx B.V]

NAND08GAH0A, NAND16GAH0D
5.3.6
5.3.7
Data Read
The DAT0-DAT7 input/outputs are High when no data is transmitted.
Data Reads allow data to be transferred from the device to the host. All Data Read
commands can be aborted at any time by the STOP_TRANSMISSION command (CMD12),
which will terminate the data transfer and return the device to the Transfer state.
The DAT bus line is High when no data is transmitted. A transmitted data block consists of a
start bit (Low), followed by a continuous data stream. The data stream contains the net
payload data (and error correction bits if a non-embedded Error Correction is used). The
data stream ends with an end bit (High) (see
transmission is synchronous to the clock signal.
The payload for block oriented data transfer is preserved by a CRC (Cyclic Redundancy
Check) check sum.
Single Block/Multiple Block Read
The command CMD17 starts a single Block Read at the address specified in the command.
After completion of the Single Block Read command, the device returns to the Transfer
state.
The command CMD18 starts a Multiple Block Read where several consecutive blocks of
data are read. The starting address is specified in the command. The blocks will be
continuously transferred until a STOP-TRANSMISSION command (CMD12) is issued. Note
that the host CMD12 command has an execution delay due to the serial command
transmission. The data transfer stops after the end bit of the CMD12 command.
The start address for a read operation can be any byte address in the valid address space of
the memory card.
During Single or Multiple Block Read operations, the basic unit of data transferred is a block
whose maximum size is defined in the CSD Register. If READ_BL_PARTIAL is set, smaller
blocks whose starting and ending address are contained within one physical block may also
be transmitted. A 16 bit CRC (Cyclic Redundancy Check) is appended to the end of each
block ensuring data transfer integrity.
Multiple Block Read operations can be of two types:
●
●
Open-ended Multiple Block Read operations
the number of blocks is not defined and the device keeps transferring data blocks until a
STOP_TRANSMISSION command is issued.
Multiple Block Read with pre-defined block count
The number of blocks to be transferred is pre-determined so the operation stops after
the pre-set number of blocks has been transmitted. When the block count is pre-
defined, the STOP_TRANSMISSION command is not required unless an error occurs.
To issue the Multiple Block Read operation with pre-defined block count, the
READ_MULTIPLE_BLOCK command must be preceded by the SET_BLOCK_COUNT
(CMD23) command, failing which the initiated Multiple Block Read operation will be
open-ended.
If all the arguments of the CMD23 command are set to 0, the command is accepted.
However, a subsequent read will follow the open-ended READ_MULTIPLE_BLOCK
operation protocol (STOP_TRANSMISSION command is required)
If the host sends a STOP-TRANSMISSION command after the last block of a multiple
block operation with a pre-defined number of blocks is transmitted, it is regarded as an
illegal command, since the device is no longer in sending data state (Data).
Figure
High speed MultiMediaCard operation
19,
Figure
20, and
Figure
21). The data
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