COTS PEM
BOOT SECTOR FLASH
Austin Semiconductor, Inc.
AS29LV016
Once erasure begins, however, the device ignores reset
commands until the operation is complete.
COMMAND DEFINITIONS
Writing specific address and data commands or
sequences into the command register initiates device
operations. Table 9 on page 21 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.
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.
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 inAC Characteristics
on page 29.
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).
READING ARRAY DATA
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).
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.
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 9
on page 21 shows the address and data requirements.
This method is an alternative to that shown in Table 4 on
page 11, which is intended for PROM programmers and
requires VID on address bit A9.
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 on page 20 for more information on
this mode.
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.
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 Reset Command, next.
A read cycle at address XX00h retrieves the manufacturer
code. A read cycle at address XX01h returns the device
code. Aread 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 Table 2 on page 9 and Table 3 on
page 10 for valid sector addresses.
See also Requirements for ReadingArray Data on page 7
for more information. The Read Operations on page 29
provides the read parameters, and Figure 12, on page 29
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 system must write the reset command to exit the
autoselect mode and return to reading array data.
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.
Austin Semiconductor, Inc. reserves the right to change products or specifications without notice.
AS29LV016
Rev. 2.1 10/08
17
AUSTIN [ AUSTIN SEMICONDUCTOR ]
