NAND08GAH0A NUMONYX [Numonyx B.V], NAND08GAH0A Datasheet - Page 86

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

Serial peripheral interface (SPI) mode
10.4.2
10.4.3
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Bus transfer protection
Every MultiMediaCard token transferred on the bus is protected by CRC (Cyclic
Redundancy Check) bits. In SPI mode, the MultiMediaCard offers a non-protected mode
which enables systems built with reliable data links to exclude the hardware or firmware
required for implementing the CRC generation and verification functions.
In the non-protected mode, the CRC bits of the command, response and data tokens are
still required in the tokens. However, they are defined as ‘don’t care’ for the transmitter and
ignored by the receiver.
The SPI interface is initialized in the non-protected mode. However, the RESET command
(CMD0), which is used to switch the device to SPI mode, is received by the device while in
MultiMediaCard mode and, therefore, must have a valid CRC field.
Since CMD0 has no arguments, the content of all the fields, including the CRC field, are
constants and need not be calculated in run time. A valid reset command is:
The host can turn the CRC option on and off using the CRC_ON_OFF command (CMD59).
Data Read
The SPI mode supports Single and Multiple Block Read operations. The main difference
between SPI and MultiMediaCard modes is that the data and the response are both
transmitted to the host on the DataOut signal (refer to
the device response to the STOP_COMMAND may cut-short and replace the last data
block.
Figure 29. SPI Single Block Read operation
0x40, 0x0, 0x0, 0x0, 0x0, 0x95
Data in
Data out
from host
command
to card
response
from card
to host
data from card
data block CRC
to host
Figure 29
NAND08GAH0A, NAND16GAH0D
and
Figure
command
command
next
30). Therefore
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