21
MBM29DL400TC
-55/-70/-90/-12
/MBM29DL400BC
-55/-70/-90/-12
When the Erase Suspend command is written during the Sector Erase operation, the device will take a maximum
of 20
μ
s to suspend the erase operation. When the devices have entered the erase-suspended mode, the RY/
BY output pin will be at Hi-Z and the DQ
7
bit will be at logic “1”, and DQ
6
will stop toggling. The user must use
the address of the erasing sector for reading DQ
6
and DQ
7
to determine if the erase operation has been
suspended. Further writes of the Erase Suspend command are ignored.
When the erase operation has been suspended, the devices default to the erase-suspend-read mode. Reading
data in this mode is the same as reading from the standard read mode except that the data must be read from
sectors that have not been erase-suspended. Successively reading from the erase-suspended sector while the
device is in the erase-suspend-read mode will cause DQ
2
to toggle. (See the section on DQ
2
.)
After entering the erase-suspend-read mode, the user can program the device by writing the appropriate
command sequence for Program. This program mode is known as the erase-suspend-program mode. Again,
programming in this mode is the same as programming in the regular Program mode except that the data must
be programmed to sectors that are not erase-suspended. Successively reading from the erase-suspended sector
while the devices are in the erase-suspend-program mode will cause DQ
2
to toggle. The end of the erase-
suspended Program operation is detected by the RY/BY output pin, Data polling of DQ
7
or by the Toggle Bit I
(DQ
6
) which is the same as the regular Program operation. Note that DQ
7
must be read from the Program address
while DQ
6
can be read from any address within bank being erase-suspended.
To resume the operation of Sector Erase, the Resume command (30H) should be written to the bank being erase
suspended. Any further writes of the Resume command at this point will be ignored. Another Erase Suspend
command can be written after the chip has resumed erasing.
Extended Command
(1) Fast Mode
MBM29DL400TC/BC has Fast Mode function. This mode dispenses with the initial two unclock cycles
required in the standard program command sequence by writing Fast Mode command into the command
register. In this mode, the required bus cycle for programming is two cycles instead of four bus cycles in
standard program command. (Do not write erase command in this mode.) The read operation is also executed
after exiting this mode. To exit this mode, it is necessary to write Fast Mode Reset command into the command
register. The first cycle must contain the bank address. (Refer to the Figure 28 Extended algorithm.) The
V
CC
active current is required even CE = V
IH
during Fast Mode.
(2) Fast Programming
During Fast Mode, the programming can be executed with two bus cycles operation. The Embedded Program
Algorithm is executed by writing program set-up command (A0H) and data write cycles (PA/PD). (Refer to
the Figure 28 Extended algorithm.)
(3) Extended Sector Protection
In addition to normal sector protection, the MBM29DL400TC/BC has Extended Sector Protection as
extended function. This function enable to protect sector by forcing V
ID
on RESET pin and write a commnad
sequence. Unlike conventional procedure, it is not necessary to force V
ID
and control timing for control pins.
The only RESET pin requires V
ID
for sector protection in this mode. The extended sector protect requires
V
ID
on RESET pin. With this condition, the operation is initiated by writing the set-up command (60H) into
the command register. Then, the sector addresses pins (A
17
, A
16
, A
15
, A
14
, A
13
and A
12
) and (A
6
, A
1
, A
0
) = (0,
1, 0) should be set to the sector to be protected (recommend to set V
IL
for the other addresses pins), and
write extended sector protect command (60H). A sector is typically protected in 150
μ
s. To verify programming
of the protection circuitry, the sector addresses pins (A
17
, A
16
, A
15
, A
14
, A
13
and A
12
) and (A
6
, A
1
, A
0
) = (0, 1,
0) should be set and write a command (40H). Following the command write, a logical “1” at device output
DQ
0
will produce for protected sector in the read operation. If the output data is logical “0”, please repeat to
write extended sector protect command (60H) again. To terminate the operation, it is necessary to set RESET
pin to V
IH
.