M29W640FT datasheet(21/72 Pages) STMICROELECTRONICS

21 / 72 page

M29W640FT, M29W640FB

4 Command Interface

21/72

During the Block Erase operation the memory will ignore all commands except the Erase

Suspend command. Typical block erase times are given in Table 7: Program, Erase Times and

Program, Erase Endurance Cycles. All Bus Read operations during the Block Erase operation

will output the Status Register on the Data Inputs/Outputs. See the section on the Status

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.

4.1.6

Erase Suspend command

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.

4.1.7

Erase Resume command

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.

4.1.8

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 Table 7: Program, Erase Times and Program, Erase Endurance Cycles for

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

M29W640FT Datasheet(PDF) 21 Page - STMicroelectronics

M29W640FT Datasheet(HTML) 21 Page - STMicroelectronics

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72

Datasheet Download

Link URL