MBM29DL800TA-70 Meet Spansion Inc., MBM29DL800TA-70 Datasheet - Page 21

• Manufacturer Part Number: MBM29DL800TA-70
• Description: Flash Memory Cmos 8m 1m ? 8 / 512k ? 16 Bit
• Manufacturer: Meet Spansion Inc.

Byte/Word Programming
Chip Erase
To terminate the operation, it is necessary to write the Read/Reset command sequence into the register, and
also to write the Autoselect command during the operation, execute it after writing Read/Reset command
sequence.
The devices are programmed on a byte-by-byte (or 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 devices return to the read mode and addresses are no longer latched. (See “Hardware
Sequence Flags Table”.) Therefore, the devices require that a valid address to the devices 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.
Any commands written to the chip during this period will be ignored. If hardware reset occurs during the
programming operation, it is impossible to guarantee the data are being 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.
“(1) Embedded Program
typical command strings and bus operations.
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 devices 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 × All sectors + Chip Program Time (Preprogramming)
“(2) Embedded Erase
command strings and bus operations.
TM
MB M29DL800TA
Algorithm” in ■FLOW CHART illustrates the Embedded Erase
TM
Algorithm” in ■FLOW CHART illustrates the Embedded Program
Retired Product DS05-20860-7E_August 6, 2007
7
is “1” (See Write Operation Status section.) at which time the
-70/90
/MBM29DL800BA
7
7
(Data Polling), DQ
is equivalent to data written to this
7
(Data Polling), DQ
TM
Algorithm using typical
TM
6
Algorithm using
(Toggle Bit), or
6
(Toggle Bit),
-70/90
21