MX29LV640BU Macronix International, MX29LV640BU Datasheet - Page 21

• Manufacturer Part Number: MX29LV640BU
• Description: 64M-BIT [4M x 16] CMOS EQUAL SECTOR FLASH MEMORY
• Manufacturer: Macronix International

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SECTOR ERASE COMMANDS
The Automatic Sector Erase does not require the
device to be entirely pre-programmed prior to
executing the Automatic Set-up Sector Erase
command and Automatic Sector Erase command.
Upon executing the Automatic Sector Erase
command, the device will automatically program and
verify the sector(s) memory for an all-zero data
pattern. The system is not required to provide any
control or timing during these operations.
When the sector(s) is automatically verified to
contain an all-zero pattern, a self-timed sector erase
and verify begin. The erase and verify operations are
complete when the data on Q7 is "1" and the data on
Q6 stops toggling for two consecutive read cycles, at
which time the device returns to the Read mode. The
system is not required to provide any control or timing
during these operations.
When using the Automatic Sector Erase algorithm,
note that the erase automatically terminates when
adequate erase margin has been achieved for the
memory array (no erase verification command is
required). Sector erase is a six-bus cycle operation.
There are two "unlock" write cycles. These are
followed by writing the set-up command 80H. Two
more "unlock" write cycles are then followed by the
sector erase command 30H. The sector address is
latched on the falling edge of WE# or CE#, whichever
happens later , while the command (data) is latched
on the rising edge of WE# or CE#, whichever happens
first. Sector addresses selected are loaded into
internal register on the sixth falling edge of WE# or
CE#, whichever happens later. Each successive
sector load cycle started by the falling edge of WE#
or CE#, whichever happens later must begin within
50us from the rising edge of the preceding WE# or
CE#, whichever happens first. Otherwise, the loading
period ends and internal auto sector erase cycle
starts. (Monitor Q3 to determine if the sector erase
timer window is still open, see section Q3, Sector
Erase Timer.) Any command other than Sector Erase
(30H) or Erase Suspend (B0H) during the time-out
period resets the device to read mode.
ERASE SUSPEND
This command only has meaning while the state ma-
chine is executing Automatic Sector Erase operation, and
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therefore will only be responded during Automatic Sector
Erase operation. When the Erase Suspend command is
issued during the sector erase operation, the device re-
quires a maximum 20us to suspend the sector erase
operation. However, When the Erase Suspend command
is written during the sector erase time-out, the device
immediately terminates the time-out period and suspends
the erase operation. After this command has been ex-
ecuted, the command register will initiate erase suspend
mode. The state machine will return to read mode auto-
matically after suspend is ready. At this time, state ma-
chine only allows the command register to respond to the
Erase Resume, program data to, or read data from any
sector not selected for erasure.
The system can determine the status of the program
operation using the Q7 or Q6 status bits, just as in the
standard program operation. After an erase-suspend pro-
gram operation is complete, the system can once again
read array data within non-suspended blocks.
ERASE RESUME
This command will cause the command register to clear
the suspend state and return back to Sector Erase mode
but only if an Erase Suspend command was previously
issued. Erase Resume will not have any effect in all
other conditions. Another Erase Suspend command can
be written after the chip has resumed erasing.
QUERY COMMAND AND COMMON FLASH
INTERFACE (CFI) MODE
MX29LV640BU is capable of operating in the CFI mode.
This mode all the host system to determine the manu-
facturer of the device such as operating parameters and
configuration. Two commands are required in CFI mode.
Query command of CFI mode is placed first, then the
Reset command exits CFI mode. These are described in
Table 3.
The single cycle Query command is valid only when the
device is in the Read mode, including Erase Suspend,
Standby mode, and Read ID mode; however, it is ignored
otherwise.
The Reset command exits from the CFI mode to the Read
mode, or Erase Suspend mode, or read ID mode. The
command is valid only when the device is in the CFI
mode.
MX29LV640BU
REV. 1.0, MAR. 08, 2005