M28W320 STMicroelectronics, M28W320 Datasheet - Page 9

• Manufacturer Part Number: M28W320
• Description: 32 Mbit 2Mb x16/ Boot Block Low Voltage Flash Memory
• Manufacturer: STMicroelectronics

INSTRUCTIONS AND COMMANDS
Sixteen instructions are available (see Tables 9
and 10) to perform Read Memory Array, Read Sta-
tus Register, Read Electronic Signature, CFI Que-
ry, Erase, Program, Double Word Program, Clear
Status Register, Program/Erase Suspend, Pro-
gram/Erase Resume, Block Protect, Block Unpro-
tect, Block Lock and Protection Register Program.
Status Register output may be read at any time,
during programming or erase, to monitor the
progress of the operation.
An internal Command Interface (C.I.) decodes the
instructions while an internal Program/Erase Con-
troller (P/E.C.) handles all timing and verifies the
correct execution of the Program and Erase in-
structions. P/E.C. provides a Status Register
whose bits indicate operation and exit status of the
internal algorithms.
The Command Interface is reset to Read Array
when power is first applied, when exiting from Re-
set or whenever V
mand sequence must be followed exactly. Any
invalid combination of commands will reset the de-
vice to Read Array.
Read (RD)
The Read instruction consists of one write cycle
(refer to Device Operations section) giving the
command FFh. Next read operations will read the
addressed location and output the data. When a
device reset occurs, the memory is in Read Array
as default.
Read Status Register (RSR)
The Status Register indicates when a program or
erase operation is complete and the success or
failure of operation itself. Issue a Read Status
Register Instruction (70h) to read the Status Reg-
ister content. The Read Status Register instruction
may be issued at any time, also when a Program/
Erase operation is ongoing. The following Read
operations output the content of the Status Regis-
ter. The Status Register is latched on the falling
edge of E or G signals, and can be read until E or
G returns to V
update the latched data. Additionally, any read at-
tempt during program or erase operation will auto-
matically output the content of the Status Register.
Read Electronic Signature (RSIG)
The Read Electronic Signature instruction con-
sists of one write cycle (refer to Device Operations
section) giving the command 90h. A subsequent
IH
. Either E or G must be toggled to
DD
is lower than V
LKO
. Com-
read will output the Manufacturer Code, the De-
vice Code, the Block protection Status, or the Pro-
tection Register. See Tables 6, 7 and 8 for the
valid address. The Electronic Signature can be
read from the memory allowing programming
equipment or applications to automatically match
their
M28W320C.
CFI Query (RCFI)
The Common Flash Interface Query mode is en-
tered by writing 98h. Next read operations will read
the CFI data. The CFI data structure contains also
a security area; in this section, a 64 bit unique se-
curity number is written, starting at this address
81h. This area can be accessed only in read mode
and there are no ways of changing the code after
it has been written by ST. Write a read instruction
to return to Read mode (refer to the Common
Flash Interface section).
Table 9. Commands
90h or 98h
Hex Code
interface
B0h
D0h
FFh
2Fh
C0h
00h
10h
20h
30h
40h
50h
70h
01h
60h
M28W320CT, M28W320CB
to
Invalid/Reserved
Alternative Program Set-up
Erase Set-up
Double Word Program Set-up
Program Set-up
Clear Status Register
Read Status Register
Read Electronic Signature, or
CFI Query
Program/Erase Suspend
Program/Erase Resume, Erase
Confirm or Unprotect Confirm
Read Array
Protect Confirm
Lock Confirm
Protection Program
Protection Set-up
the
Command
characteristics
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of