m58lw032d STMicroelectronics, m58lw032d Datasheet - Page 14

• Manufacturer Part Number: m58lw032d
• Description: 32 Mbit 4mb X8, 2mb X16, Uniform Block 3v Supply Flash Memory
• Manufacturer: STMicroelectronics

M58LW032D
COMMAND INTERFACE
All Bus Write operations to the memory are inter-
preted by the Command Interface. Commands
consist of one or more sequential Bus Write oper-
ations. The Commands are summarized in
4.,
with the text descriptions below.
After power-up or a Reset operation the memory
enters Read mode.
Read Memory Array Command. The Read Mem-
ory Array command is used to return the memory
to Read mode. One Bus Write cycle is required to
issue the Read Memory Array command and re-
turn the memory to Read mode. Once the com-
mand is issued the memory remains in Read
mode until another command is issued. From
Read mode Bus Read operations will access the
memory array. After power-up or a reset the mem-
ory defaults to Read Array mode (Page Read).
While the Program/Erase Controller is executing a
Program, Erase, Block Protect, Blocks Unprotect
or Protection Register Program operation the
memory will not accept the Read Memory Array
command until the operation completes.
Read Electronic Signature Command. The Read
Electronic Signature command is used to read the
Manufacturer Code, the Device Code, the Block
Protection Status and the Protection Register.
One Bus Write cycle is required to issue the Read
Electronic Signature command. Once the com-
mand is issued subsequent Bus Read operations
read the Manufacturer Code, the Device Code, the
Block Protection Status or the Protection Register
until another command is issued. Refer to
6., Read Electronic
Word and Byte-wide Read Protection Register
and
for information on the addresses.
Read Query Command. The Read Query Com-
mand is used to read data from the Common Flash
Interface (CFI) Memory Area. One Bus Write cycle
is required to issue the Read Query Command.
Once the command is issued subsequent Bus
Read operations read from the Common Flash In-
terface Memory Area. See
24, 25, 26, 27,
mation contained in the Common Flash Interface
(CFI) memory area.
Read Status Register Command. The Read Sta-
tus Register command is used to read the Status
Register. One Bus Write cycle is required to issue
the Read Status Register command. Once the
command is issued subsequent Bus Read opera-
tions read the Status Register until another com-
mand is issued.
14/50
Commands. Refer to
Figure 6., Protection Register Memory
28
and
Signature, Tables
29
Table 4.
for details on the infor-
APPENDIX
in conjunction
B., Tables
7
and 8,
Table
Table
Map,
The Status Register information is present on the
output data bus (DQ1-DQ7) when the device is en-
abled and Output Enable is Low, V
See the section on the Status Register and
10.
ister bits
Clear Status Register Command. The Clear Sta-
tus Register command can be used to reset bits
SR1, SR3, SR4 and SR5 in the Status Register to
‘0’. One Bus Write is required to issue the Clear
Status Register command.
The bits in the Status Register are sticky and do
not automatically return to ‘0’ when a new Write to
Buffer and Program, Erase, Block Protect, Block
Unprotect or Protection Register Program com-
mand is issued. If any error occurs then it is essen-
tial to clear any error bits in the Status Register by
issuing the Clear Status Register command before
attempting a new Program, Erase or Resume
command.
Block Erase Command. The Block Erase com-
mand can be used to erase a block. It sets all of
the bits in the block to ‘1’. All previous data in the
block is lost. If the block is protected then the
Erase operation will abort, the data in the block will
not be changed and the Status Register will output
the error.
Two Bus Write operations are required to issue the
command; the second Bus Write cycle latches the
block address and starts the Program/Erase Con-
troller. Once the command is issued subsequent
Bus Read operations read the Status Register.
See the section on the Status Register for details
on the definitions of the Status Register bits.
During the Erase operation the memory will only
accept the Read Status Register command and
the Program/Erase Suspend command. All other
commands will be ignored. Typical Erase times
are given in
See
and Pseudo
using the Block Erase command.
Word/Byte Program Command. The
Byte Program command is used to program a sin-
gle Word or Byte in the memory array. Two Bus
Write operations are required to issue the com-
mand; the first write cycle sets up the Word Pro-
gram command, the second write cycle latches the
address and data to be programmed, and starts
the Program/Erase Controller.
If the block being programmed is protected an er-
ror will be set in the Status Register and the oper-
ation will abort without affecting the data in the
memory array. The block must be unprotected us-
ing the Blocks Unprotect command or by using the
for details on the definitions of the Status Reg-
APPENDIX
Table 9.
Code, for a suggested flowchart on
C.,
Figure 18., Erase Flowchart
IL
.
Word/
Table