Octorber 18, 2004 S29GLxxxM_00_B3
S29GLxxxM MirrorBit
TM
Flash Family
103
D a t a s h e e t
Command Definitions
Writing specific address and data commands or sequences into the command register initiates device operations.
Table 35 on page 113
and
Table 36 on page 114
define the valid register command sequences.
Writing incorrect
address and data values or writing them in the improper sequence may place the device in an unknown state.
A
reset command is then required to return 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
“AC Characteristics” on page 124
section for
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. The device is 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-read mode, after
which the system can read data from any non-erase-suspended sector. After completing a programming operation
in the Erase Suspend mode, the system may once again read array data with the same exception. See the
“Erase
Suspend/Erase Resume Commands” on page 111
section for more information.
The system
must
issue the reset command to return the device to the read (or erase-suspend-read) mode if DQ5
goes high during an active program or erase operation, or if the device is in the autoselect mode. See the next
section, Reset Command, for more information.
See also
“Requirements for Reading Array Data” on page 30
in the Device Bus Operations section for more infor-
mation. The Read-Only Operations–
“AC Characteristics” on page 124
provides the read parameters, and
Figure 13, on page 126
shows the timing diagram.
Reset Command
Writing the reset command resets the device 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 device to the read mode. Once erasure begins, however, the device ignores reset com-
mands until the operation is complete.
The reset command may be written between the sequence cycles in a program command sequence before pro-
gramming begins. This resets the device to the read mode. If the program command sequence is written while
the device is in the Erase Suspend mode, writing the reset command returns the device to the erase-suspend-
read 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 the read mode. If the device entered the
autoselect mode while in the Erase Suspend mode, writing the reset command returns the device to the erase-
suspend-read mode.
If DQ5 goes high during a program or erase operation, writing the reset command returns the device to the read
mode (or erase-suspend-read mode if the device was in Erase Suspend).
Note that if DQ1 goes high during a Write Buffer Programming operation, the system must write the Write-to-
Buffer-Abort Reset command sequence to reset the device for the next operation.