Numonyx™ StrataFlash® Cellular Memory (M18)
9.4.4
CFI Query
Issuing the CFI Query command places the addressed partition in CFI Query mode.
Subsequent reads from that partition output CFI information.
The addressed partition remains in CFI Query mode until a different read command is
issued, or a program or erase operation is performed, which changes the read mode to
Read Status Register mode.
Note:
Issuing the CFI Query command to a partition that is actively programming or erasing
changes that partition’s read mode to CFI Query mode. Subsequent reads from that
partition will return invalid data until the program or erase operation has completed.
The CFI Query command functions independent of the voltage level on VPP.
9.5
Programming Modes
To understand programming modes, it is also important to understand the fundamental
memory array configuration. The flash device main array is divided as follows:
• The main array of the 128-Mbit device is divided into eight 16-Mbit partitions. Each
parition is divided into eight 256-KByte blocks: 8 x 8 = 64 blocks in the main array
of a 128-Mbit device.
• The main array of the 256-Mbit device is divided into eight 32-Mbit partitions. Each
partition is divided into sixteen 256-KByte blocks: 8 x 16 = 128 blocks in the main
array of a 256-Mbit device.
• The main array of the 512-Mbit device is divided into eight 64-Mbit partitions. Each
partition is divided into thirty-two 256-KByte blocks: 8 x 32 = 256 blocks in the
main array of a 256-Mbit device.
• The main array of the 1-Gbit device is divided into eight 128-Mbit partitions. Each
partition is divided into sixty-four 256-KByte blocks: 8 x 64 = 512 blocks in the
main array of a 1-Gbit device.
Each block is divided into as many as two-hundred-fifty-six 1-KByte programming
regions. Each region is divided into as many as thirty-two 32-Byte segments.
Each programming region in a flash block can be configured for one of two
programming modes: Control Mode or Object Mode. The programming mode is
automatically set based on the data pattern when a region is first programmed. The
selection of either Control Mode or Object Mode is done according to the specific needs
of the system with consideration given to two types of information:
• Control Mode: Flash File System (FFS) or Header information, including frequently
changing code or data
• Object Mode: Large, infrequently changing code or data, such as objects or
payloads
By implementing the appropriate programming mode, software can efficiently organize
how information is stored in the flash memory array.
Control Mode programming regions and Object Mode programming regions can be
intermingled within the same erase block. However, the programming mode of any
region within a block can be changed only after erasing the entire block.
April 2008
309823-10
Datasheet
83
NUMONYX [ NUMONYX B.V ]
