MX29F040
ERASE SUSPEND
This command only has meaning while the state machine
is executing Automatic Sector Erase operation, and
therefore will only be responded during Automatic Sector
Erase operation. When the Erase Suspend command is
written during a sector erase operation, the device 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 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 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
program operation is complete, the system can once
again read array data within non-suspended sectors.
If the program opetation was unsuccessful, the data on
Q5 is "1"(see Table 4), indicating the program operation
exceed internal timing limit. The automatic programming
operation is completed when the data read on Q6 stops
toggling for two consecutive 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).
DATA POLLING-Q7
The MX29F040 also features Data Polling as a method
to indicate to the host system that the Automatic Program
or Erase algorithms are either in progress or completed.
While the Automatic Programming algorithm is in
operation, an attempt to read the device will produce the
complement data of the data last written to Q7. Upon
completion of the Automatic Program Algorithm an
attempt to read the device will produce the true data last
written to Q7. The Data Polling feature is valid after the
rising edge of the fourth WE or CE, whichever happeds
first pulse of the four write pulse sequences for automatic
program.
While the Automatic Erase algorithm is in operation, Q7
will read "0" until the erase operation is competed. Upon
completion of the erase operation, the data on Q7 will
read "1". The Data Polling feature is valid after the rising
edge of the sixth WE or CE, whichever happeds first
pulse of six write pulse sequences for automatic chip/
sector erase.
The Data Polling feature is active during Automatic
Program/Erase algorithm or sector erase time-out.(see
section Q3 Sector Erase Timer)
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.
SET-UP AUTOMATIC PROGRAM
COMMANDS
To initiate Automatic Program mode, A three-cycle
command sequence is required. There are two "unlock"
write cycles. These are followed by writing the Automatic
Program command A0H.
Once the Automatic Program command is initiated, the
next WE or CE pulse causes a transition to an active
programming operation. Addresses are latched on the
falling edge, and data are internally latched on the rising
edge of the WE or CE, whichever happeds first pulse.
The rising edge of WE or CE, whichever happeds 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.
P/N:PM0538
REV. 1.6, AUG. 08, 2001
9
MCNIX [ MACRONIX INTERNATIONAL ]
