MX29F022 Macronix, MX29F022 Datasheet - Page 10

• Manufacturer Part Number: MX29F022
• Description: 2M-BIT[256K x 8]CMOS FLASH MEMORY
• Manufacturer: Macronix

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 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 program-
ming operation. Addresses are latched on the falling
edge, and data are internally latched on the rising
edge of the WE pulse. The rising edge of WE also be-
gins the programming operation. The system does not
require to provide further controls or timings. The de-
vice will automatically provide an adequate internally
generated program pulse and verify margin.
If the program opetation was unsuccessful, the data on
Q5 is "1", indicating the program operation of internally
exceed timing limit. The automatic programming opera-
tion is complete when the data read on Q6 stops tog-
gling 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).
WRITE OPERATION STATUS DATA POLLING-Q7
The MX29F022T/B 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 second WE pulse of the two write pulse
sequences.
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While the Automatic Erase algorithm is in operation, Q7
will read "0" until the erase operation is compete. 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 secone WE pulse of two write pulse se-
quences.
The Data Polling feature is active during Automatic Pro-
gram/Erase algorithm or sector erase time-out.(see sec-
tion Q3 Sector Erase Timer)
Q6:Toggle BIT I
The MX29F022T/B features a "Toggle Bit" as a method
to indicate to the host system that the Auto Program/
Erase algorithms are either in progress or complete.
During an Automatic Program or Erase algorithm op-
eration, successive read cycles to any address cause
Q6 to toggle. The system may use either OE or CE to
control the read cycles. When the operation is complete,
Q6 stops toggling.
After an erase command sequence is written, if the chip
is protected, Q6 toggles and returns to reading array
data.
The system can use Q6 and Q2 together to determine
whether a sector is actively erasing or is erase sus-
pended. When the device is actively erasing (that is, the
Automatic Erase algorithm is in progress), Q6 toggling.
When the device enters the Erase Suspend mode, Q6
stops toggling. However, the system must also use Q2
to determine which sectors are erasing or erase-sus-
pended. Alternatively, the system can use Q7(see the
subsection on Q7:Data Polling).
If a program address falls within a protected sector, Q6
toggles for approximately 2us after the program com-
mand sequence is written, then returns to reading array
data.
Q6 also toggles during the erase-suspend-program
mode, and stops toggling once the Automatic Program
algorithm is complete.
The Write Operation Status table shows the outputs for
Toggle Bit I on Q6. Refer to the toggle bit algorithmg.
MX29F022/022N
REV. 1.1, JUN. 14, 2001