m28w320bb STMicroelectronics, m28w320bb Datasheet - Page 12

• Manufacturer Part Number: m28w320bb
• Description: 32 Mbit 2mb X16, Boot Block 3v Supply Flash Memory
• Manufacturer: STMicroelectronics

M28W320BT, M28W320BB
commands will be ignored. Typical Program times
are given in Table 6, Program, Erase Times and
Program/Erase Endurance Cycles.
Programming aborts if Reset goes to V
integrity cannot be guaranteed when the program
operation is aborted, the block containing the
memory location must be erased and repro-
grammed.
See Appendix C, Figure 16, 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 17, Double Word Pro-
gram Flowchart and Pseudo Code, for the flow-
chart for using the Double 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.
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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.
PP
PP
is not at V
is below V
PPH
PPH
. The command can be
but the result is not
IL
. As data integrity
IL
. As data
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 command will also be accepted. Only
the blocks not being erased may be read or pro-
grammed 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 18, Program Suspend &
Resume Flowchart and Pseudo Code, and Figure
20, 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-
quent Bus Read operations read the Status Reg-
ister.
See Appendix C, Figure 18, Program or Double
Word Program Suspend & Resume Flowchart and
Pseudo Code, and Figure 20, Erase Suspend &
Resume Flowchart and Pseudo Code for flow-
charts for using the Program/Erase Resume com-
mand.
Block Protection
Two parameter/lockable blocks (blocks #0 and #1)
can be protected against Program or Erase oper-
ations. Unprotected blocks can be programmed or
erased.
To protect the two lockable blocks set Write Pro-
tect to V
protected. Any attempt to Program or Erase pro-
tected blocks will abort, the data in the block will
not be changed and the Status Register outputs
the error.
Table 5, Memory Blocks Protection Truth Table,
defines the protection methods.
IL
. When V
IL
.
IH
PP
. Program/Erase is aborted if
is below V
PPLK
all blocks are