August 28, 2002
Am45DL32x8G
27
PR ELI M I NARY
FLASH COMMAND DEFINITIONS
Writing specific address and data commands or se-
quences into the command register initiates device op-
erations. Tables
16 and
18 define the valid register
command sequences. Writing incorrect address and
data values or writing them in the improper se-
quence resets the device to reading array data.
All addresses are latched on the falling edge of WE#
or CE#f, whichever happens later. All data is latched
on the rising edge of WE# or CE#f, whichever hap-
timing diagrams.
Reading Array Data
The device is automatically set to reading array data
after device power-up. No commands are required to
retrieve data. Each bank is ready to read array data
after completing an Embedded Program or Embedded
Erase algorithm.
After the device accepts an Erase Suspend command,
the c orres ponding bank enters the er ase-s us-
pend-read mode, after which the system can read
data from any non-erase-suspended sector within the
same bank. The system can read array data using the
standard read timing, except that if it reads at an ad-
dress within erase-suspended sectors, the device out-
puts status data. After completing a programming
operation in the Erase Suspend mode, the system
may once again read array data with the same excep-
mands section for more information.
The system must issue the reset command to return a
bank to the read (or erase-suspend-read) mode if DQ5
goes high during an active program or erase opera-
tion, or if the bank is in the autoselect mode. See the
14 shows the timing diagram.
Reset Command
Writing the reset command resets the banks to the
read or erase-suspend-read mode. Address bits are
don’t cares for this command.
The reset command may be written between the se-
quence cycles in an erase command sequence before
erasing begins. This resets the bank to which the sys-
tem was writing to the read mode. Once erasure be-
gins, 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 bank to
which the system was writing to the read mode. If the
program command sequence is written to a bank that
is in the Erase Suspend mode, writing the reset
c omm an d r et ur ns t hat ba nk to t he e r as e -s us -
pend-read mode. Once programming begins, how-
ever, the device ignores reset commands until the
operation is complete.
The reset command may be written between the se-
quence cycles in an autoselect command sequence.
Once in the autoselect mode, the reset command
must be written to return to the read mode. If a bank
entered the autoselect mode while in the Erase Sus-
pend mode, writing the reset command returns that
bank to the erase-suspend-read mode.
If DQ5 goes high during a program or erase operation,
writing the reset command returns the banks to the
read mode (or erase-suspend-read mode if that bank
was in Erase Suspend).
Autoselect Command Sequence
The autoselect command sequence allows the host
system to access the manufacturer and device codes,
and determine whether or not a sector is protected.
The autoselect command sequence may be written to
an address within a bank that is either in the read or
erase-suspend-read mode. The autoselect command
may not be written while the device is actively pro-
gramming or erasing in the other bank.
The autoselect command sequence is initiated by first
writing two unlock cycles. This is followed by a third
write cycle that contains the bank address and the au-
toselect command. The bank then enters the autose-
lect mode. The system may read any number of
autoselect codes without reinitiating the command se-
quence.
Tables
16 and
18 show the address and data require-
ments. To determine sector protection information, the
system must write to the appropriate bank address
(BA) and sector address (SADD). Tables
6 and
8 show
the address range and bank number associated with
each sector.
The system must write the reset command to return to
the read mode (or erase-suspend-read mode if the
bank was previously in Erase Suspend).
Enter SecSi Sector/Exit SecSi Sector
Command Sequence
The SecSi Sector region provides a secured data area
containing a random, sixteen-byte electronic serial
number (ESN). The system can access the SecSi
Sector region by issuing the three-cycle Enter SecSi
Sector command sequence. The device continues to
access the SecSi Sector region until the system is-