MBM29LV160T Fujitsu Media Devices, MBM29LV160T Datasheet - Page 20

• Manufacturer Part Number: MBM29LV160T
• Description: 16M (2M x 8/1M x 16) BIT
• Manufacturer: Fujitsu Media Devices

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MBM29LV160T
Erase Suspend/Resume
Sector erase is a six-bus cycle operation. There are two “unlock” write cycles, followed by writing the “set-up”
command. Two more “unlock” write cycles are then followed by the Sector Erase command. The sector address
(any address location within the desired sector) is latched on the falling edge of WE, while the command (Data
= 30H) is latched on the rising edge of WE. After a time-out of 50 s from the rising edge of the last sector erase
command, the sector erase operation will begin.
Multiple sectors may be erased concurrently by writing six-bus cycle operations on Table 7. This sequence is
followed with writes of the Sector Erase command to addresses in other sectors desired to be concurrently
erased. The time between writes must be less than 50 s otherwise that command will not be accepted and
erasure will start. It is recommended that processor interrupts be disabled during this time to guarantee this
condition. The interrupts can be re-enabled after the last Sector Erase command is written. A time-out of 50 s
from the rising edge of the last WE will initiate the execution of the Sector Erase command(s). If another falling
edge of the WE occurs within the 50 s time-out window the timer is reset. Monitor DQ
erase timer window is still open. (See section DQ
or Erase Suspend during this time-out period will reset the device to the read mode, ignoring the previous
command string. Resetting the device once excution has begun will corrupt the data in the sector. In that case,
restart the erase on those sectors and allow them to complete. (Refer to the Write Operation Status section for
Sector Erase Timer operation.) Loading the sector erase buffer may be done in any sequence and with any
number of sectors (0 to 34).
Sector erase does not require the user to program the device prior to erase. The device automatically programs
all memory locations in the sector(s) to be erased prior to electrical erase (Preprogram Function). When erasing
a sector or sectors the remaining unselected sectors are not affected. The system is not required to provide any
controls or timings during these operations. (See Figure 8.)
The automatic sector erase begins after the 50 s time out from the rising edge of the WE pulse for the last
sector erase command pulse and terminates when the data on DQ
at which time the device returns to the read mode. Data polling must be performed at an address within any of
the sectors being erased. Multiple Sector Erase Time; [Sector Program Time (Preprogramming) + Sector Erase
Time]
Figure 21 illustrates the Embedded Erase
The Erase Suspend command allows the user to interrupt a Sector Erase operation and then perform data reads
from or program to a sector not being erased. This command is applicable ONLY during the Sector Erase
operation which includes the time-out period for sector erase. The Erase Suspend command will be ignored if
written during the Chip Erase operation or Embedded Program Algorithm. Writting the Erase Suspend command
during the Sector Erase time-out results in immediate termination of the time-out period and suspension of the
erase operation.
Writing the Erase Resume command resumes the erase operation. The addresses are “DON’T CARES” when
writing the Erase Suspend or Erase Resume commands.
When the Erase Suspend command is written during the Sector Erase operation, the device will take a maximum
of 20 s to suspend the erase operation. When the devices have entered the erase-suspended mode, the RY/
BY output pin and the DQ
the erasing sector for reading DQ
writes of the Erase Suspend command are ignored.
When the erase operation has been suspended, the device defaults 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
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
Number of Sector Erase.
7
bit will be at logic “1”, and DQ
-80/-90/-12
6
and DQ
TM
7
to determine if the erase operation has been suspended. Further
Algorithm using typical command strings and bus operations.
/MBM29LV160B
3
, Sector Erase Timer.) Any command other than Sector Erase
6
2
will stop toggling. The user must use the address of
to toggle. (See the section on DQ
7
is “1” (See Write Operation Status section)
-80/-90/-12
3
to determine if the sector
2
.)