AM29LV800DT-90ED Spansion Inc., AM29LV800DT-90ED Datasheet - Page 19

• Manufacturer Part Number: AM29LV800DT-90ED
• Description: Flash Memory IC
• Manufacturer: Spansion Inc.
• Series: AM29r

Specifications of AM29LV800DT-90ED

• Memory Size: 8Mbit
• Package/case: 48-TSOP
• Supply Voltage Max: 3V
• Leaded Process Compatible: Yes
• Peak Reflow Compatible (260 C): Yes
• Access Time, Tacc: 90nS
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

Note: See Table 5 for program command sequence.
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. Table 5 shows
the address and data requirements for the chip erase
command sequence.
Any commands written to the chip during the Embed-
ded Erase algorithm are ignored. Note that a hard-
w a r e r e s e t d u r i n g t h e c h i p e r a s e o p e r a t i o n
immediately terminates the operation. The Chip Erase
command sequence should be reinitiated once the de-
Am29LV800D_00_A6 May 5, 2006
Increment Address
Figure 3. Program Operation
in progress
Embedded
algorithm
Program
No
Command Sequence
Write Program
Last Address?
Programming
from System
Verify Data?
Completed
Data Poll
START
Yes
Yes
D A T A
No
Am29LV800D
S H E E T
vice has returned to reading array data, to ensure data
integrity.
The system can determine the status of the erase op-
eration by using DQ7, DQ6, DQ2, or RY/BY#. See
“Write Operation Status” for information on these sta-
tus bits. When the Embedded Erase algorithm is com-
plete, the device returns to reading array data and
addresses are no longer latched.
Figure 4 illustrates the algorithm for the erase opera-
tion. See the
Characteristics” for parameters, and to Figure 18 for
timing diagrams.
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 write cycles are then followed by the
address of the sector to be erased, and the sector
erase command. Table 5 shows the address and data
requirements for the sector erase command se-
quence.
The device does not require the system to preprogram
the memory prior to erase. The Embedded Erase al-
gorithm automatically programs and verifies the sector
for an all zero data pattern prior to electrical erase.
The system is not required to provide any controls or
timings during these operations.
After the command sequence is written, a sector erase
time-out of 50 µs begins. 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 the last address and command might
not be accepted, and erasure may begin. 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. If the time between addi-
tional sector erase commands can be assumed to be
less than 50 µs, the system need not monitor DQ3.
Any command other than Sector Erase or Erase
Suspend during the time-out period resets the de-
vice to reading array data. The system must rewrite
the command sequence and any additional sector ad-
dresses and commands.
The system can monitor DQ3 to determine if the sec-
tor erase timer has timed out. (See the “DQ3: Sector
Erase Timer” section.) The time-out begins from the
rising edge of the final WE# pulse in the command se-
quence.
Erase/Program Operations
tables in “AC
17