MBM29PDS322TE Fujitsu Microelectronics, Inc., MBM29PDS322TE Datasheet - Page 24

• Manufacturer Part Number: MBM29PDS322TE
• Description: Flash Memory 32m 2m X 16 Bit Page Dual Operation
• Manufacturer: Fujitsu Microelectronics, Inc.

24
MBM29PDS322TE/BE
Word Programming
Chip Erase
The device is programmed on a word-by-word basis. Programming is a four bus cycle operation. There are two
“unlock” write cycles. These are followed by the program set-up command and data write cycles. Addresses are
latched on the falling edge of CE or WE, whichever happens later and the data is latched on the rising edge of
CE or WE, whichever happens first. The rising edge of CE or WE (whichever happens first) begins programming.
Upon executing the Embedded Program Algorithm command sequence, the system is not required to provide
further controls or timings. The device will automatically provide adequate internally generated program pulses
and verify the programmed cell margin.
The system can determine the status of the program operation by using DQ
or RY/BY. The Data Polling and Toggle Bit must be performed at the memory location which is being programmed.
The automatic programming operation is completed when the data on DQ
bit at which time the device returns to the read mode and addresses are no longer latched. (See Table 9, Hardware
Sequence Flags.) Therefore, the device requires that a valid address to the device be supplied by the system
at this particular instance of time. Hence, Data Polling must be performed at the memory location which is being
programmed.
written.
Programming is allowed in any sequence and across sector boundaries. Beware that a data “0” cannot be
programmed back to a “1”. Attempting to do so may either hang up the device or result in an apparent success
according to the data polling algorithm but a read from Read/Reset mode will show that the data is still “0”. Only
erase operations can convert “0”s to “1”s.
Figure 20 illustrates the Embedded Program
Chip 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 chip erase command.
Chip erase does not require the user to program the device prior to erase. Upon executing the Embedded Erase
Algorithm command sequence the device will automatically program and verify the entire memory for an all 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 read the mode.
Chip Erase Time; Sector Erase Time
Figure 21 illustrates the Embedded Erase
If hardware reset occurs during the programming operation, it is impossible to guarantee the data are being
All sectors + Chip Program Time (Preprogramming)
TM
Algorithm using typical command strings and bus operations.
TM
10/11
Algorithm using typical command strings and bus operations.
7
is “1” (See Write Operation Status section.) at which time the
7
7
(Data Polling), DQ
is equivalent to data written to this
7
(Data Polling), DQ
6
(Toggle Bit), or
6
(Toggle Bit),