Numonyx™ StrataFlash® Cellular Memory (M18)
Note:
Issuing the Read Array command to a partition that is actively erasing a main block
causes subsequent reads from that partition to output invalid data. Valid array data is
output only after the block-erase operation has finished.
Standby power levels are not realized until the block-erase operation has finished.
Asserting RST# immediately aborts the block-erase operation, and array contents at
the addressed location are indeterminate. The addressed block should be erased, and
the data re-programmed.
9.8
Blank Check Operation
Blank Check is used to see if a main-array block is completely erased. A Blank Check
operation is performed one block at a time, and cannot be used during Program
Suspend or Erase Suspend.
To use Blank Check, first issue the Blank Check setup command followed by the confirm
command. The read mode of the addressed partition is automatically changed to Read
Status Register mode, which remains in effect until another read-mode command is
issued.
Table 42: Blank Check Command Bus Cycles
Setup Write Cycle
Address Bus Data Bus
Block Address 00BCh
Confirm Write Cycle
Command
Address Bus
Data Bus
00D0h
Blank Check
Block Address
During a blank check operation, the Status Register indicates a busy status (SR7 = 0).
Upon completion, the Status Register indicates a ready status (SR7 = 1).
Note:
Issuing the Read Status Register command to another partition switches that partition’s
read mode to Read Status Register mode, thereby allowing the blank check operation
to be monitored from that partition’s address.
The Status Register should be checked for any errors, and then cleared. If the Blank
Check operation fails, i.e., the block is not completely erased, then the Status Register
will indicate a Blank Check error (SR[7,5] = 1).
The only valid command during a Blank Check operation is Read Status. Blank Check
cannot be suspended. After the blank check operation has completed, any valid
command can be issued.
9.9
Suspend and Resume
Program and erase operations of the main array can be suspended to perform other
device operations, and then subsequently resumed. However, OTP Register
programming or blank check operations cannot be suspended.
To suspend an on-going erase or program operation, issue the Suspend command to
any device address; the corresponding partition is not affected. Table 43 shows the
Suspend and Resume command bus-cycles.
Note:
Issuing the Suspend command does not change the read mode of the partition. The
partition will be in Read Status Register mode from when the erase or program
command was first issued, unless the read mode was changed prior to issuing the
Suspend command.
April 2008
309823-10
Datasheet
93
NUMONYX [ NUMONYX B.V ]
