M28F201-120K1R STMICROELECTRONICS [STMicroelectronics], M28F201-120K1R Datasheet - Page 4

• Manufacturer Part Number: M28F201-120K1R
• Description: 2 Mb 256K x 8, Chip Erase FLASH MEMORY
• Manufacturer: STMICROELECTRONICS [STMicroelectronics]

M28F201
Table 5. Commands
Notes: 1. X = V
Standby Mode. In the Standby Mode the maxi-
mum supply current is reduced. The device is
placed in the Standby Mode by applying a High
level to the Chip Enable (E) input. When in the
Standby Mode the outputs are in a high impedance
state, independant of the Output Enable (G) input.
Output Disable Mode. When the Output Enable
(G) is High the outputs are in a high impedance
state.
Electronic Signature Mode. This mode allows the
read out of two binary codes from the device which
identify the manufacturer and device type. This
mode is intended for use by programming equip-
ment to automatically select the correct erase and
programming algorithms. The Electronic Signature
Mode is active when a high voltage (11.5V to 13V)
is applied to address line A9 with E and G Low. With
A0 Low the output data is the manufacturer code,
when A0 is High the output is the device code. All
other address lines should be maintained Low
while reading the codes. The electronic signature
can also be accessed in Read/Write modes.
READ/WRITE MODES, 11.4V V
When V
may be performed. These are defined by the con-
tents of an internal command register. Commands
may be written to this register to set-up and exe-
cute, Erase, Erase Verify, Program, Program Verify
and Reset modes. Each of these modes needs 2
cycles. Each mode starts with a write operation to
set-up the command, this is followed by either read
or write operations. The device expects the first
cycle to be a write operation and does not corrupt
4/21
Read
Electronic
Signature
Setup Erase/
Erase
Erase Verify
Setup Program/
Program
Program Verify
Reset
Command
2. Refer also to the Electronic Signature table.
PP
(2)
is High both read and write operations
IL
or V
IH
.
Cycles
1
2
2
2
2
2
2
(1)
Operation
Write
Write
Write
Write
Write
Write
Write
PP
12.6V
1st Cycle
A0-A17
A0-A17
X
X
X
X
X
X
80h or 90h
DQ0-DQ7
data at any location in the memory. Read mode is
set-up with one cycle only and may be followed by
any number of read operations to output data.
Electronic Signature Read mode is set-up with one
cycle and followed by a read cycle to output the
manufacturer or device codes.
Awrite to the command register is made by bringing
W Low while E is Low. The falling edge of W latches
Addresses, while the rising edge latches Data,
which are used for those commands that require
address inputs, command input or provide data
output. The supply voltage V
voltage V
device is powered up or when V
contents of the command register defaults to 00h,
thus automatically setting-up Read operations. In
addition a specific command may be used to set
the command register to 00h for reading the mem-
ory. The system designer may chose to provide a
constant high V
for all operations, or to switch the V
high only when needing to erase or program the
memory. All command register access is inhibited
when V
age (V
If the device is deselected during Erasure, Pro-
gramming or verifying it will draw active supply
currents until the operations are terminated.
The device is protected against stress caused by
long erase or program times. If the end of Erase or
Programming operations are not terminated by a
Verify cycle within a maximum time permitted, an
internal stop timer automatically stops the opera-
tion. The device remains in an inactive state, ready
to start a Verify or Reset Mode operation.
C0h
A0h
FFh
00h
20h
40h
LKO
CC
PP
) of 2.5V.
falls below the Erase/Write Lockout Volt-
Operation
can be applied in any order. When the
Read
Read
Read
Read
Write
Write
Write
PP
and use the register commands
A0-A17
00000h
00001h
A0-A17
2nd Cycle
X
X
X
X
CC
and the program
PP
PP
Data Output
Data Output
is
Data Input
DQ0-DQ7
from low to
20h
F4h
20h
FFh
6.5V the