NAND08GAH0A NUMONYX [Numonyx B.V], NAND08GAH0A Datasheet - Page 92

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

Serial peripheral interface (SPI) mode
10.4.8
10.4.9
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Clock control
The SPI bus clock signal can be used by the SPI host to put the device into energy saving
mode or to control the data flow (to avoid under-run or over-run conditions) on the bus. The
host is allowed to change the clock frequency or shut it down.
There are a few restrictions the SPI host must follow:
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The various SPI bus transactions are listed below:
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Error conditions
CRC and illegal command
All commands are (optionally) protected by CRC (cyclic redundancy check) bits. If the
addressed MultiMediaCard's CRC check fails, the COM_CRC_ERROR bit is set in the
device response. Similarly, if an illegal command has been received the
ILLEGAL_COMMAND bit is set in the device response.
There are different kinds of illegal commands:
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The bus frequency can be changed at any time (under the restrictions of maximum
data transfer frequency, defined by the MultiMediaCards)
The clock must be running for the MultiMediaCard to output data or response tokens.
After the last SPI bus transaction, the host must provide 8 (eight) clock cycles for the
device to complete the operation before shutting down the clock. Throughout this 8-
clock period the state of the CS signal is irrelevant, it can be asserted or de-asserted.
A command / response sequence, 8 clocks after the device response end bit. The CS
signal can be asserted or de-asserted during these 8 clocks
A read data transaction, 8 clocks after the end bit of the last data block
A write data transaction, 8 clocks after the CRC status token
The host is allowed to shut down the clock of a “busy” device. The MultiMediaCard
completes the programming operation regardless of the host clock. However, the host
must provide a clock edge for the device to turn off its busy flag. Without a clock edge
the MultiMediaCard (unless previously disconnected by de-asserting the CS signal) will
force the DataOut line Low, permanently.
Commands that belong to classes not supported by the MultiMediaCard (like interrupt
and I/O commands)
Commands not allowed in SPI mode
Commands that are not defined (like CMD47).
NAND08GAH0A, NAND16GAH0D