AM29BDS320G SPANSION [SPANSION], AM29BDS320G Datasheet - Page 32

• Manufacturer Part Number: AM29BDS320G
• Description: 32 Megabit (2 M x 16-Bit), 1.8 Volt-only Simultaneous Read/Write, Burst Mode Flash Memory
• Manufacturer: SPANSION [SPANSION]

30
Reset Command
Autoselect Command Sequence
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 sequence 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 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 (prior to the third cycle). This re-
sets 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, writ-
ing the reset command returns that bank to the erase-suspend-read mode. Once
programming begins, however, the device ignores reset commands until the op-
eration 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 the read mode. If a bank entered the autoselect mode while
in the Erase Suspend 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).
The reset command is used to exit the sector lock/unlock sequence. This com-
mand is required before reading from the bank selected for sector lock/unlock
operations.
The autoselect command sequence allows the host system to access the manu-
facturer and device codes, and determine whether or not a sector is protected.
Table 14, “Command Definitions,” on page 36
quirements. 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 autose-
lect command may not be written while the device is actively programming 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 autoselect mode. No subsequent
data will be made available if the autoselect data is read in synchronous mode.
The system may read at any address within the same bank any number of times
without initiating another autoselect command sequence. The following table de-
scribes the address requirements for the various autoselect functions, and the
resulting data. BA represents the bank address, and SA represents the sector ad-
dress. The device ID is read in three cycles.
Am29BDS320G
P r e l i m i n a r y
shows the address and data re-
27243B1 October 1, 2003