MX29LV002NCT Macronix International, MX29LV002NCT Datasheet - Page 13

• Manufacturer Part Number: MX29LV002NCT
• Description: 2M-BIT [256K x 8] CMOS SINGLE VOLTAGE 3V ONLY FLASH MEMORY
• Manufacturer: Macronix International

still "0". Only erase operations can convert a "0" to a
"1".
WRITE OPERATION STATUS
The device provides several bits to determine the sta-
tus of a write operation: Q2, Q3, Q5, Q6, Q7, and RY/
BY#. Table 10 and the following subsections describe
the functions of these bits. Q7, RY/BY#, and DQ6 each
offer a method for determining whether a program or erase
operation is complete or in progress. These three bits
are discussed first. Please note that RY/BY# pin is pro-
vided for 40-pin TSOP package type only.
Q7: Data# Polling
The Data# Polling bit, Q7, indicates to the host sys-tem
whether an Automatic Algorithm is in progress or com-
pleted, or whether the device is in Erase Suspend. Data#
Polling is valid after the rising edge of the final WE# pulse
in the program or erase command sequence.
During the Automatic Program algorithm, the device out-
puts on Q7 the complement of the datum programmed
to Q7. This Q7 status also applies to programming dur-
ing Erase Suspend. When the Automatic Program algo-
rithm is complete, the device outputs the datum pro-
grammed to Q7. The system must provide the program
address to read valid status information on Q7. If a pro-
gram address falls within a protected sector, Data# Poll-
ing on Q7 is active for approximately 1 us, then the de-
vice returns to reading array data.
During the Automatic Erase algorithm, Data# Polling pro-
duces a "0" on Q7. When the Automatic Erase algo-
rithm is complete, or if the device enters the Erase Sus-
pend mode, Data# Polling produces a "1" on Q7. This is
analogous to the complement/true datum out-put de-
scribed for the Automatic Program algorithm: the erase
function changes all the bits in a sector to "1" prior to
this, the device outputs the "complement," or "0". The
system must provide an address within any of the sec-
tors selected for erasure to read valid status information
on Q7.
After an erase command sequence is written, if all sec-
tors selected for erasing are protected, Data# Polling on
Q7 is active for approximately 100 us, then the device
returns to reading array data. If not all selected sectors
are protected, the Automatic Erase algorithm erases the
P/N:PM1204
MX29LV002C/002NC T/B
13
unprotected sectors, and ignores the selected sectors
that are protected.
When the system detects Q7 has changed from the
complement to true data, it can read valid data at Q7-Q0
on the following read cycles. This is because Q7 may
change asynchronously with Q0-Q6 while Output En-
able (OE#) is asserted low.
RY/BY#:Ready/Busy#
only)
The RY/BY# is a dedicated, open-drain output pin that
indicates whether an Automatic Erase/Program algorithm
is in progress or complete. The RY/BY# status is valid
after the rising edge of the final WE# or CE#, whichever
happens first, in the command sequence. Since RY/BY#
is an open-drain output, several RY/BY# pins can be tied
together in parallel with a pull-up resistor to Vcc.
If the output is low (Busy), the device is actively erasing
or programming. (This includes programming in the Erase
Suspend mode.) If the output is high (Ready), the de-
vice is ready to read array data (including during the
Erase Suspend mode), or is in the standby mode.
Table 7 shows the outputs for RY/BY# during write op-
eration.
Q6:Toggle BIT I
Toggle Bit I on Q6 indicates whether an Automatic Pro-
gram or Erase algorithm is in progress or complete, or
whether the device has entered the Erase Suspend mode.
Toggle Bit I may be read at any address, and is valid
after the rising edge of the final WE# or CE#, whichever
happens first, in the command sequence (prior to the
program or erase operation), and during the sector time-
out.
During an Automatic Program or Erase algorithm opera-
tion, 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 all sec-
tors selected for erasing are protected, Q6 toggles and
returns to reading array data. If not all selected sectors
are protected, the Automatic Erase algorithm erases the
(for 32-pin TSOP package
www.DataSheet4U.com
REV. 1.0, JUN. 30, 2005