M29W640FB STMICROELECTRONICS [STMicroelectronics], M29W640FB Datasheet - Page 21

• Manufacturer Part Number: M29W640FB
• Description: 64 Mbit (8Mb x8 or 4Mb x16, Page, Boot Block) 3V Supply Flash Memory
• Manufacturer: STMICROELECTRONICS [STMicroelectronics]

M29W640FT, M29W640FB
4.1.6
4.1.7
4.1.8
Erase Suspend command
Erase Resume command
During the Block Erase operation the memory will ignore all commands except the Erase
Suspend command. Typical block erase times are given in
Program, Erase Endurance
will output the Status Register on the Data Inputs/Outputs. See the section on the Status
Register for more details.
After the Block Erase operation has completed the memory will return to the Read Mode,
unless an error has occurred. When an error occurs the memory will continue to output the
Status Register. A Read/Reset command must be issued to reset the error condition and return
to Read mode.
The Block Erase Command sets all of the bits in the unprotected selected blocks to ’1’. All
previous data in the selected blocks is lost.
The Erase Suspend Command may be used to temporarily suspend a Block Erase operation
and return the memory to Read mode. The command requires one Bus Write operation.
The Program/Erase Controller will suspend within the Erase Suspend Latency time of the
Erase Suspend Command being issued. Once the Program/Erase Controller has stopped the
memory will be set to Read mode and the Erase will be suspended. If the Erase Suspend
command is issued during the period when the memory is waiting for an additional block
(before the Program/Erase Controller starts) then the Erase is suspended immediately and will
start immediately when the Erase Resume Command is issued. It is not possible to select any
further blocks to erase after the Erase Resume.
During Erase Suspend it is possible to Read and Program cells in blocks that are not being
erased; both Read and Program operations behave as normal on these blocks. If any attempt is
made to program in a protected block or in the suspended block then the Program command is
ignored and the data remains unchanged. The Status Register is not read and no error
condition is given. Reading from blocks that are being erased will output the Status Register.
It is also possible to issue the Auto Select, Read CFI Query and Unlock Bypass commands
during an Erase Suspend. The Read/Reset command must be issued to return the device to
Read Array mode before the Resume command will be accepted.
The Erase Resume command must be used to restart the Program/Erase Controller after an
Erase Suspend. The device must be in Read Array mode before the Resume command will be
accepted. An erase can be suspended and resumed more than once.
Program Suspend command
The Program Suspend command allows the system to interrupt a program operation so that
data can be read from any block. When the Program Suspend command is issued during a
program operation, the device suspends the program operation within the Program Suspend
Latency time (see
value) and updates the Status Register bits.
After the program operation has been suspended, the system can read array data from any
address. However, data read from Program-Suspended addresses is not valid.
The Program Suspend command may also be issued during a program operation while an
erase is suspended. In this case, data may be read from any addresses not in Erase Suspend
Table 7: Program, Erase Times and Program, Erase Endurance Cycles
Cycles. All Bus Read operations during the Block Erase operation
Table 7: Program, Erase Times and
4 Command Interface
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