NAND08GAH0A NUMONYX [Numonyx B.V], NAND08GAH0A Datasheet - Page 26

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

High speed MultiMediaCard operation
5.2.2
5.2.3
5.2.4
26/116
Input/output voltage range validation
All device communicate with the host using an input/output voltage in the V
V
are defined in the operation condition register (OCR) and may not cover the whole range.
The SEND_OP_COND (CMD1) command is designed to provide hosts with a mechanism
to identify and reject devices which do not match the desired V
by the host sending the required V
Section 8.1: Operation conditions register
transfer in the specified range, it switches into the Inactive state. Otherwise, the device
answers sending back its V
By omitting the voltage range when issuing the CMD1 command (by setting CMD1
argument to ‘0’), the host queries the device about its input/output voltage range. This bus
query should be used if the host is able to select a common voltage range, or if the
application needs to be notified of non usable devices connected to the bus. The host then
chooses an operating voltage, and reissues the CMD1 together with this condition, sending
incompatible devices into the Inactive state.
From Busy to Ready state
The busy flag in the CMD1 response can be used by the device to notify the host that the
power-up/reset sequence is still ongoing and that the device is not ready for communication.
In this case the host must reissue the CMD1 command until the busy flag is cleared.
During the initialization procedure, the host should not change the operating voltage range
or access mode settings. Any change in the operating conditions is ignored by the device. If
this case, the host must reset the device by issuing a CMD0 command, and restart the
initialization sequence. However, a hardware reset must be performed for accessing devices
that are already in the Inactive state.
The GO_INACTIVE_STATE (CMD15) command can be used to send an addressed device
into the Inactive state. This command is used when the host explicitly wants to de-activate a
device by changing its V
device.
Card Identification process
This process is valid when multiple MultiMediaCard devices are connected to the bus.
The host starts the card identification process in open-drain mode with the identification
clock rate f
allow parallel operation during card identification.
After the bus is activated, the host will request the devices to send its valid operating
conditions (CMD1). The response to CMD1 is the ‘wired and’ operation on the condition
restrictions of all devices in the system. Incompatible devices are sent into Inactive state.
The host then issues the broadcast command CMD2 and asks all devices for their unique
Card Identification (CID) number. All remaining unidentified devices simultaneously start
sending their CID numbers serially, while monitoring their outgoing bit stream. The devices,
whose outgoing CID bits do not match the corresponding bits on the command line, stop
sending their CID immediately and wait for the next identification cycle (devices stay in the
Ready state). Since CID numbers are unique for each device, there should be only one
device which successfully sends its full CID-number to the host. This device then goes into
the Identification state.
CCQmax
range. In Card Identification mode, the minimum and maximum values for V
OD
(see
Table 9: Bus AC
CC
CCQ
range into a range which is known not to be supported by this
range.
CCQ
timings). The open drain driver stages on the CMD line
range as the operand of the CMD1 command (see
(OCR)). If the device can not perform data
NAND08GAH0A, NAND16GAH0D
CCQ
range. This is performed
CCQmin
and
CCQ