MX29LV400T/B
AUTOMATIC ERASE ALGORITHM
AUTOMATIC PROGRAMMING
MXIC's Automatic Erase algorithm requires the user to
write commands to the command register using stan-
dard microprocessor write timings. The device will auto-
matically pre-program and verify the entire array. Then
the device automatically times the erase pulse width,
provides the erase verification, and counts the number
of sequences. A status bit toggling between consecu-
tive read cycles provides feedback to the user as to the
status of the erasing operation.
The MX29LV400T/B is byte programmable using the Au-
tomatic Programming algorithm. The Automatic Pro-
gramming algorithm makes the external system do not
need to have time out sequence nor to verify the data
programmed. The typical chip programming time at room
temperature of the MX29LV400T/B is less than 10 sec-
onds.
AUTOMATIC CHIP ERASE
Register contents serve as inputs to an internal state-
machine which controls the erase and programming cir-
cuitry. During write cycles, the command register inter-
nally latches address and data needed for the program-
ming and erase operations. During a system write cycle,
addresses are latched on the falling edge, and data are
latched on the rising edge of WE or CE, whichever hap-
pens first.
The entire chip is bulk erased using 10 ms erase pulses
according to MXIC's Automatic Chip Erase algorithm.
Typical erasure at room temperature is accomplished in
less than 25 second. The Automatic Erase algorithm
automatically programs the entire array prior to electri-
cal erase. The timing and verification of electrical erase
are controlled internally within the device.
MXIC's Flash technology combines years of EPROM
experience to produce the highest levels of quality, reli-
ability, and cost effectiveness.The MX29LV400T/B elec-
trically erases all bits simultaneously using Fowler-
Nordheim tunneling. The bytes are programmed by us-
ing the EPROM programming mechanism of hot elec-
tron injection.
AUTOMATIC SECTOR ERASE
The MX29LV400T/B is sector(s) erasable using MXIC's
Auto Sector Erase algorithm. The Automatic Sector
Erase algorithm automatically programs the specified
sector(s) prior to electrical erase. The timing and verifi-
cation of electrical erase are controlled internally within
the device. An erase operation can erase one sector,
multiple sectors, or the entire device.
During a program cycle, the state-machine will control
the program sequences and command register will not
respond to any command set. During a Sector Erase
cycle, the command register will only respond to Erase
Suspend command. After Erase Suspend is completed,
the device stays in read mode. After the state machine
has completed its task, it will allow the command regis-
ter to respond to its full command set.
AUTOMATIC PROGRAMMING ALGORITHM
MXIC's Automatic Programming algorithm requires the
user to only write program set-up commands (including
2 unlock write cycle and A0H) and a program command
(program data and address). The device automatically
times the programming pulse width, provides the pro-
gram verification, and counts the number of sequences.
The device provides an unlock bypass mode with faster
programming. Only two write cycles are needed to pro-
gram a word or byte, instead of four. A status bit similar
to DATA polling and a status bit toggling between con-
secutive read cycles, provide feedback to the user as
to the status of the programming operation. Refer to write
operation status, table7, for more information on these
status bits.
AUTOMATIC SELECT
The automatic select mode provides manufacturer and
device identification, and sector protection verification,
through identifier codes output on Q7~Q0.This mode is
mainly adapted for programming equipment on the de-
vice to be programmed with its programming algorithm.
When programming by high voltage method, automatic
select mode requires VID (11.5V to 12.5V) on address
pin A9 and other address pin A6, A1 as referring toTable
3. In addition, to access the automatic select codes in-
system, the host can issue the automatic select com-
P/N:PM0710
REV. 1.4, NOV. 23, 2001
5
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