AM29PDLI27H SPANSION [SPANSION], AM29PDLI27H Datasheet - Page 38

• Manufacturer Part Number: AM29PDLI27H
• Description: 128 Megabit (8 M x 16-Bit) CMOS 3.0 Volt-only, Page Mode Simultaneous Read/Write Flash Memory with Enhanced VersatileIO Control
• Manufacturer: SPANSION [SPANSION]

Chip Erase Command Sequence
Chip erase is a six bus cycle operation. The chip erase
command sequence is initiated by writing two unlock
cycles, followed by a set-up command. Two additional
unlock write cycles are then followed by the chip erase
command, which in turn invokes the Embedded Erase
algorithm. The device does not require the system to
preprogram prior to erase. The Embedded Erase algo-
rithm automatically preprograms and verifies the entire
memory for an all zero data pattern prior to electrical
erase. The system is not required to provide any con-
trols or timings during these operations.
shows the address and data requirements for the chip
erase command sequence.
When the Embedded Erase algorithm is complete,
that bank returns to the read mode and addresses are
no longer latched. The system can determine the sta-
tus of the erase operation by using DQ7, DQ6, DQ2,
or RY/BY#. Refer to the
tion for information on these status bits.
Any commands written during the chip erase operation
are ignored. Note that SecSi Sector, autoselect, and
CFI functions are unavailable when a [program/erase]
36
Note: See
Increment Address
Table 13
Figure 4. Program Operation
Embedded
in progress
algorithm
Program
for program command sequence.
Write Operation Status
No
Command Sequence
Write Program
A D V A N C E
Last Address?
Programming
from System
Verify Data?
Completed
Data Poll
START
Yes
Yes
Table 13
No
Am29PDL127H
sec-
I N F O R M A T I O N
operation is in progress. However, note that a hard-
ware reset immediately terminates the erase opera-
tion. If that occurs, the chip erase command sequence
should be reinitiated once that bank has returned to
reading array data, to ensure data integrity.
Figure 5 illustrates the algorithm for the erase opera-
tion. Refer to the
bles in the AC Characteristics section for parameters,
and
Sector Erase Command Sequence
Sector erase is a six bus cycle operation. The sector
erase command sequence is initiated by writing two
unlock cycles, followed by a set-up command. Two ad-
ditional unlock cycles are written, and are then fol-
lowed by the address of the sector to be erased, and
the sector erase
dress and data requirements for the sector erase com-
mand sequence.
The device does not require the system to preprogram
prior to erase. The Embedded Erase algorithm auto-
matically programs and verifies the entire memory for
an all zero data pattern prior to electrical erase. The
system is not required to provide any controls or tim-
ings during these operations.
After the command sequence is written, a sector erase
time-out of 50 µs occurs. During the time-out period,
additional sector addresses and sector erase com-
mands may be written. Loading the sector erase buffer
may be done in any sequence, and the number of sec-
tors may be from one sector to all sectors. The time
between these additional cycles must be less than 50
µs, otherwise erasure may begin. Any sector erase
address and command following the exceeded
time-out may or may not be accepted. It is recom-
mended that processor interrupts be disabled during
this time to ensure all commands are accepted. The
interrupts can be re-enabled after the last Sector
Erase command is written. Any command other than
S e ct o r E ra se o r E ra s e S u s p en d d u r i n g th e
time-out period resets that bank to the read mode.
The system must rewrite the command sequence and
any additional addresses and commands. Note that
SecSi Sector, autoselect, and CFI functions are un-
available when a [program/erase] operation is in
progress.
The system can monitor DQ3 to determine if the sec-
tor erase timer has timed out (See the section on DQ3:
Sector Erase Timer). The time-out begins from the ris-
ing edge of the final WE# pulse in the command
sequence.
When the Embedded Erase algorithm is complete, the
bank returns to reading array data and addresses are
no longer latched. Note that while the Embedded
Erase operation is in progress, the system can read
Figure 17
section for timing diagrams.
command.Table 13
Erase and Program Operations
shows the ad-
June 30, 2003
ta-