MX29LV800BT Macronix, MX29LV800BT Datasheet - Page 15

• Manufacturer Part Number: MX29LV800BT
• Description: 8M-Bit CMOS Single Voltage 3V Only Flash Memory
• Manufacturer: Macronix

SECTOR ERASE COMMANDS
The Automatic Sector Erase does not require the de-
vice to be entirely pre-programmed prior to executing
the Automatic Sector Erase Set-up command and Au-
tomatic Sector Erase command. Upon executing the
Automatic Sector Erase command, the device will auto-
matically 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 either the data on Q7 is "1" at which time the de-
vice returns to the Read mode, or 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 "un-
lock" 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 succes-
sive 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#, which-
ever 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 therefore will only be responded during Automatic
Sector Erase operation. When the Erase Suspend Com-
mand is issued during the sector erase operation, the
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device requires a maximum 20us to suspend the sector
erase operation. However, when the Erase Suspend com-
mand 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 executed, the command register will initiate erase
suspend mode. The state machine will return to read
mode automatically after suspend is ready. At this time,
state machine only allows the command register to re-
spond to 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 sectors.
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. However,
a delay time must be required after the erase resume
command (1.5ms for MX29LV800BT/BB), if the system
implements an endless erase suspend/resume loop, or
the number of erase suspend/resume is exceeded 1024
times. The erase times will be expended if the erase
behavior always be suspended. (Please refer to MXIC
Flash Application Note for details.)
WORD/BYTE PROGRAM COMMAND SEQUENCE
The device programs one byte of data for each program
operation. The command sequence requires four bus
cycles, and is initiated by writing two unlock write cycles,
followed by the program set-up command. The program
address and data are written next, which in turn initiate
the Embedded Program algorithm. The system is
required to provide further controls or timings. The device
automatically generates the program pulses and verifies
the programmed cell margin. Table 1 shows the address
and data requirements for the byte program command
sequence.
When the Embedded Program algorithm is complete,
the device then returns to reading array data and
addresses are no longer latched. The system can
MX29LV800BT/BB
REV. 1.3, DEC. 20, 2004
not