
October 10, 2006  21521D6
Am29LV200B
15
D AT A  S H E E T
COMMAND DEFINITIONS
Writing specific address and data commands or 
sequences into the command register initiates device 
operations. Table 5 defines the valid register command 
sequences. Writing 
incorrect
address and data 
values
 or writing them in the 
improper sequence
resets the device to reading array data. 
All addresses are latched on the falling edge of WE# or 
CE#, whichever happens later. All data is latched on 
the rising edge of WE# or CE#, whichever happens 
first. Refer to the appropriate timing diagrams in the 
“AC Characteristics” section.
Reading Array Data
The device is automatically set to reading array data 
after device power-up. No commands are required to 
retrieve data. The device is also ready to read array 
data after completing an Embedded Program or 
Embedded Erase algorithm.
After the device accepts an Erase Suspend command, 
the device enters the Erase Suspend mode. The 
system can read array data using the standard read 
timings, except that if it reads at an address within 
erase-suspended sectors, the device outputs status 
data. After completing a programming operation in the 
Erase Suspend mode, the system may once again 
read array data with the same exception. See “Erase 
Suspend/Erase Resume Commands” for more infor-
mation on this mode.
The system 
must
 issue the reset command to re-
enable the device for reading array data if DQ5 goes 
high, or while in the autoselect mode. See the “Reset 
Command” section, next.
See also “Requirements for Reading Array Data” in the 
“Device Bus Operations” section for more information. 
The Read Operations table provides the read parame-
ters, and Figure 13 shows the timing diagram.
Reset Command
Writing the reset command to the device resets the 
device to reading array data. Address bits are don’t 
care for this command. 
The reset command may be written between the 
sequence cycles in an erase command sequence 
before erasing begins. This resets the device to reading 
array data. Once erasure begins, however, the device 
ignores reset commands until the operation is 
complete.
The reset command may be written between the 
sequence cycles in a program command sequence 
before programming begins. This resets the device to 
reading array data (also applies to programming in 
Erase Suspend mode). Once programming begins, 
however, the device ignores reset commands until the 
operation is complete.
The reset command may be written between the 
sequence cycles in an autoselect command sequence. 
Once in the autoselect mode, the reset command 
must
be written to return to reading array data (also applies 
to autoselect during Erase Suspend).
If DQ5 goes high during a program or erase operation, 
writing the reset command returns the device to 
reading array data (also applies during Erase 
Suspend).
Autoselect Command Sequence
The autoselect command sequence allows the host 
system to access the manufacturer and devices codes, 
and determine whether or not a sector is protected. 
Table 5 shows the address and data requirements. This 
method is an alternative to that shown in Table 4, which 
is intended for PROM programmers and requires V
ID
on address bit A9.
The autoselect command sequence is initiated by 
writing two unlock cycles, followed by the autoselect 
command. The device then enters the autoselect 
mode, and the system may read at any address any 
number of times, without initiating another command 
sequence. A read cycle at address XX00h retrieves the 
manufacturer code. A read cycle at address XX01h in 
word mode (or 02h in byte mode) returns the device 
code. A read cycle containing a sector address (SA) 
and the address 02h in word mode (or 04h in byte 
mode) returns 01h if that sector is protected, or 00h if it 
is unprotected. Refer to Tables 2 and 3 for valid sector 
addresses.
The system must write the reset command to exit the 
autoselect mode and return to reading array data.
Word/Byte Program Command Sequence
The system may program the device by word or byte, 
depending on the state of the BYTE# pin. Program-
ming is a four-bus-cycle operation. The program 
command sequence is initiated by writing two unlock 
write cycles, followed by the program set-up command. 
The program address and data are written next, which 
in turn initiate the Embedded Program algorithm. The 
system is 
not
 required to provide further controls or tim-
ings. The device automatically generates the program 
pulses and verifies the programmed cell margin. Table 
5 shows the address and data requirements for the 
byte program command sequence.
When the Embedded Program algorithm is complete, 
the device then returns to reading array data and 
addresses are no longer latched. The system can 
determine the status of the program operation by using