mx26l6420 Macronix International Co., mx26l6420 Datasheet - Page 11

• Manufacturer Part Number: mx26l6420
• Description: 64m-bit [4m X 16] Cmos Multiple-time-programmable Eprom
• Manufacturer: Macronix International Co.

P/N:PM0823
READING ARRAY DATA
The device is automatically set to reading array data
after device power-up. No commands are required to
retrieve data. The device is also ready to read array data
after completing an Automatic Program or Automatic
Erase algorithm.
The system
able the device for reading array data if Q5 goes high, or
while in the autoselect mode. See the "Reset Command"
section, next.
RESET COMMAND
Writing the reset command to the device resets the
device to reading array data. Address bits are don't care
for this command.
The reset command may be written between the se-
quence cycles in an erase command sequence before
erasing begins. This resets the device to reading array
data. Once erasure begins, however, the device ignores
reset commands until the operation is complete.
The reset command may be written between the se-
quence cycles in a program command sequence before
programming begins. This resets the device to reading
array data. Once programming begins,however, the device
ignores reset commands until the operation is complete.
The reset command may be written between the se-
quence cycles in an SILICON ID READ command
sequence. Once in the SILICON ID READ mode, the
reset command
data.
If Q5 goes high during a program or erase operation,
writing the reset command returns the device to reading
array data.
SILICON ID READ COMMAND SEQUENCE
The SILICON ID READ command sequence allows the
host system to access the manufacturer and devices
codes, and determine whether or not. Table 4 shows the
address and data requirements. This method is an
alternative to that shown in Table 1, which is intended for
EPROM programmers and requires V
A9.
The SILICON ID READ command sequence is initiated
must issue the reset command to re-en-
must be written to return to reading array
ID
on address bit
11
by writing two unlock cycles, followed by the SILICON
ID READ command. The device then enters the SILICON
ID READ mode, and the system may read at any address
any number of times, without init iating another command
sequence. A read cycle at address XX00h retrieves the
manufacturer code. A read cycle at address XX01h re-
turns the device code.
The system must write the reset command to exit the
autoselect mode and return to reading array data.
WORD PROGRAM COMMAND SEQUENCE
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
to provide fur ther controls or timings. The device
automatically generates the program pulses and verifies
the programmed cell margin. Table 4 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, 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 Word 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. A bit cannot
be programmed from a "0" back to a "1". Cause the Data
Polling algorithm to indicate the operation was successful.
However, a succeeding read will show that the data is
still "0". Only erase operations can convert a "0" to a
"1".
MX26L6420
REV. 0.5, JAN. 29, 2002
not required