MBM29DL640E Fujitsu Microelectronics, Inc., MBM29DL640E Datasheet - Page 30

• Manufacturer Part Number: MBM29DL640E
• Description: Flash Memory 64 M 8 M X 8/4 M X 16 Bit Dual Operation
• Manufacturer: Fujitsu Microelectronics, Inc.

30
MBM29DL640E
Sector Erase
Erase Suspend/Resume
zero data pattern prior to electrical erase (Preprogram function) . The system is not required to provide any
controls or timings during these operations.
The system can determine the status of the erase operation by using DQ
RY/BY. The chip erase begins on the rising edge of the last CE or WE, whichever happens first in the command
sequence, and terminates when the data on DQ
device returns to the read mode.
Chip Erase Time; Sector Erase Time
Figure 23 illustrates the Embedded Erase
Sector erase is a six bus cycle operation. There are two “unlock” write cycles. These are 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 CE or WE, whichever
happens later, while the command (Data
first. After time-out of “t
begins.
Multiple sectors may be erased concurrently by writing the six bus cycle operations on Table 4. This sequence
is followed by writes of the Sector Erase command to addresses in other sectors desired to be concurrently
erased. The time between writes must be less than “t
erasure will not start. It is recommended that processor interrupts be disabled during this time to guarantee such
a condition. The interrupts can reoccur after the last Sector Erase command is written. A time-out of “t
the rising edge of last CE or WE, whichever happens first, will initiate the execution of the Sector Erase command
(s) . If another falling edge of CE or WE, whichever happens first occurs within the “t
timer is reset (monitor DQ
Erase Timer). Resetting the device once execution 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 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
RY/BY.
The sector erase begins after the “t
the last sector erase command pulse and terminates when the data on DQ
section), at which time the device returns to the read mode. Data polling and Toggle Bit must be performed at
an address within any of the sectors being erased.
Multiple Sector Erase Time
Sector Erase
In case of multiple sector erase across bank boundaries, a read from the bank (read-while-erase) to which
sectors being erased belong cannot be performed.
Figure 23 illustrates the Embedded Erase
The Erase Suspend command allows the user to interrupt Sector Erase operation and then reads data from or
programs 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. Writing the Erase Suspend command (B0h) during the Sector
Erase time-out results in immediate termination of the time-out period and suspension of the erase operation.
sectors (0 to 141) .
Sector erase does not require the user to program the device before 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, the rest remain unaffected. The system is not required to provide any controls or timings during these
operations.
The system can determine the status of the erase operation by using DQ
TOW
3
” from the rising edge of the last sector erase command, the sector erase operation
to determine if the sector erase timer window is still open, see section DQ
80/90/12
[Sector Erase Time
TOW
” time-out from the rising edge of CE or WE, whichever happens first, for
All sectors
TM
TM
30h) is latched on the rising edge of CE or WE, whichever happens
Algorithm using typical command strings and bus operations.
Algorithm using typical command strings and bus operations.
7
is “1” (see Write Operation Status section), at which time the
Chip Program Time (Preprogramming)
Sector Program Time (Preprogramming) ]
TOW
”. Otherwise, that command will not be accepted and
7
7
7
(Data Polling) , DQ
(Data Polling) , DQ
is “1” (see Write Operation Status
TOW
” time-out window, the
6
6
(Toggle Bit) or
(Toggle Bit) or
Number of
TOW
3
, Sector
” from