MX29LV040 Macronix, MX29LV040 Datasheet - Page 12

• Manufacturer Part Number: MX29LV040
• Description: 4M-Bit CMOS Single Voltage 3V Flash Memory
• Manufacturer: Macronix

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 written during a sector erase operation, the de-
vice requires a maximum of 100us to suspend the erase
operations. 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 Read Memory Array, Erase Resume and program
commands.
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 10ms time delay must be required after the erase re-
sume command, if the system implements an endless
erase suspend/resume loop, or the number of erase sus-
pend/resume is exceeded 1024 times. The erase times
will be expended if the erase behavior always be sus-
pended. (Please refer to MXIC Flash Application Note
for details.)
AUTOMATIC PROGRAM COMMANDS
To initiate Automatic Program mode, A three-cycle com-
mand sequence is required. There are two "unlock" write
cycles. These are followed by writing the Automatic Pro-
gram command A0H.
Once the Automatic Program command is initiated, the
next WE# pulse causes a transition to an active pro-
gramming operation. Addresses are latched on the fall-
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12
ing edge, and data are internally latched on the rising
edge of the WE# or CE#, whichever happens first. The
rising edge of WE# or CE#, whichever happens first,
also begins the programming operation. The system is
not required to provide further controls or timings. The
device will automatically provide an adequate internally
generated program pulse and verify margin.
The device provides Q2, Q3, Q5, Q6, Q7 to determine
the status of a write operation. If the program operation
was unsuccessful, the data on Q5 is "1" (see Table 6),
indicating the program operation exceed internal timing
limit. The automatic programming operation is completed
when the data read on Q6 stops toggling for two con-
secutive read cycles and the data on Q7 and Q6 are
equivalent to data written to these two bits, at which
time the device returns to the Read mode(no program
verify command is required).
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 3 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
determine the status of the program operation by using
Q7, or Q6. See "Write Operation Status" for information
on these status bits.
Any commands written to the device during the Em-
bedded Program Algorithm are ignored. Note that a
hardware reset immediately terminates the programming
operation. The Byte Program command sequence should
be reinitiated once the device has reset to reading array
data, to ensure data integrity.
Programming is allowed in any sequence and across
sector boundaries. A bit cannot be programmed from a
"0" back to a "1". Attempting to do so may halt the
operation and set Q5 to "1", or cause the Data# Polling
algorithm to indicate the operation was successful.
However, a succeeding read will show that the data is
MX29LV040
REV. 1.3, DEC. 20, 2004
not