M28W640 STMicroelectronics, M28W640 Datasheet - Page 12

• Manufacturer Part Number: M28W640
• Description: 64 Mbit 4Mb x16/ Boot Block 3V Supply Flash Memory
• Manufacturer: STMicroelectronics

M28W640CT, M28W640CB
memory location must be erased and repro-
grammed.
See Appendix C, Figure 17, Program Flowchart
and Pseudo Code, for the flowchart for using the
Program command.
Double Word Program Command
This feature is offered to improve the programming
throughput, writing a page of two adjacent words
in parallel.The two words must differ only for the
address A0. Programming should not be attempt-
ed when V
executed if V
guaranteed.
Three bus write cycles are necessary to issue the
Double Word Program command.
Read operations output the Status Register con-
tent after the programming has started. Program-
ming aborts if Reset goes to V
cannot be guaranteed when the program opera-
tion is aborted, the block containing the memory
location must be erased and reprogrammed.
See Appendix C, Figure 18, Double Word Pro-
gram Flowchart and Pseudo Code, for the flow-
chart for using the Double Word Program
command.
Quadruple Word Program Command
This feature is offered to improve the programming
throughput, writing a page of four adjacent words
in parallel.The four words must differ only for the
addresses A0 and A1. Programming should not be
attempted when V
can be executed if V
is not guaranteed.
Five bus write cycles are necessary to issue the
Quadruple Word Program command.
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The first bus cycle sets up the Double Word
Program Command.
The second bus cycle latches the Address and
the Data of the first word to be written.
The third bus cycle latches the Address and the
Data of the second word to be written and starts
the Program/Erase Controller.
The first bus cycle sets up the Double Word
Program Command.
The second bus cycle latches the Address and
the Data of the first word to be written.
The third bus cycle latches the Address and the
Data of the second word to be written.
The fourth bus cycle latches the Address and
the Data of the third word to be written.
The fifth bus cycle latches the Address and the
Data of the fourth word to be written and starts
the Program/Erase Controller.
PP
PP
is not at V
is below V
PP
PP
is not at V
is below V
PPH
PPH
. The command can be
IL
PPH
but the result is not
. As data integrity
PPH
. The command
but the result
Read operations output the Status Register con-
tent after the programming has started. Program-
ming aborts if Reset goes to V
cannot be guaranteed when the program opera-
tion is aborted, the block containing the memory
location must be erased and reprogrammed.
See Appendix C, Figure 19, Quadruple Word Pro-
gram Flowchart and Pseudo Code, for the flow-
chart for using the Quadruple Word Program
command.
Clear Status Register Command
The Clear Status Register command can be used
to reset bits 1, 3, 4 and 5 in the Status Register to
‘0’. One bus write cycle is required to issue the
Clear Status Register command.
The bits in the Status Register do not automatical-
ly return to ‘0’ when a new Program or Erase com-
mand is issued. The error bits in the Status
Register should be cleared before attempting a
new Program or Erase command.
Program/Erase Suspend Command
The Program/Erase Suspend command is used to
pause a Program or Erase operation. One bus
write cycle is required to issue the Program/Erase
command and pause the Program/Erase control-
ler.
During Program/Erase Suspend the Command In-
terface will accept the Program/Erase Resume,
Read Array, Read Status Register, Read Electron-
ic Signature and Read CFI Query commands. Ad-
ditionally, if the suspend operation was Erase then
the Program, Double Word Program, Quadruple
Word Program, Block Lock, Block Lock-Down or
Protection Program commands will also be ac-
cepted. The block being erased may be protected
by issuing the Block Protect, Block Lock or Protec-
tion Program commands. When the Program/
Erase Resume command is issued the operation
will complete. Only the blocks not being erased
may be read or programmed correctly.
During a Program/Erase Suspend, the device can
be placed in a pseudo-standby mode by taking
Chip Enable to V
Reset turns to V
See Appendix C, Figure 20, Program Suspend &
Resume Flowchart and Pseudo Code, and Figure
22, Erase Suspend & Resume Flowchart and
Pseudo Code for flowcharts for using the Program/
Erase Suspend command.
Program/Erase Resume Command
The Program/Erase Resume command can be
used to restart the Program/Erase Controller after
a Program/Erase Suspend operation has paused
it. One Bus Write cycle is required to issue the
command. Once the command is issued subse-
IL
.
IH
. Program/Erase is aborted if
IL
. As data integrity