MX29LV320MB Macronix International, MX29LV320MB Datasheet - Page 12

• Manufacturer Part Number: MX29LV320MB
• Description: 32M-BIT [4M x 8/2M x 16] SINGLE VOLTAGE 3V ONLY FLASH MEMORY
• Manufacturer: Macronix International

REQUIREMENTS FOR READING ARRAY
DATA
To read array data from the outputs, the system must
drive the CE# and OE# pins to VIL. CE# is the power
control and selects the device. OE# is the output control
and gates array data to the output pins. WE# should re-
main at VIH.
The internal state machine is set for reading array data
upon device power-up, or after a hardware reset. This
ensures that no spurious alteration of the memory con-
tent occurs during the power transition. No command is
necessary in this mode to obtain array data. Standard
microprocessor read cycles that assert valid address on
the device address inputs produce valid data on the de-
vice data outputs. The device remains enabled for read
access until the command register contents are altered.
PAGE MODE READ
The MX29LV320MT/B offers "fast page mode read" func-
tion. This mode provides faster read access speed for
random locations within a page. The page size of the de-
vice is 4 words/8 bytes. The appropriate page is selected
by the higher address bits A0~A1(Word Mode)/A-
1~A1(Byte Mode) This is an asynchronous operation; the
microprocessor supplies the specific word location.
The system performance could be enhanced by initiating
1 normal read and 3 fast page read (for word mode A0-
A1) or 7 fast page read (for byte mode A-1~A1). When
CE# is deasserted and reasserted for a subsequent ac-
cess, the access time is tACC or tCE. Fast page mode
accesses are obtained by keeping the "read-page ad-
dresses" constant and changing the "intra-read page"
addresses.
WRITING
QUENCES
To program data to the device or erase sectors of memory,
the system must drive WE# and CE# to VIL, and OE# to
VIH.
An erase operation can erase one sector, multiple sec-
tors, or the entire device. Table indicates the address
space that each sector occupies. A "sector address"
P/N:PM1129
COMMANDS/COMMAND
SE-
12
consists of the address bits required to uniquely select a
sector. The "Writing specific address and data commands
or sequences into the command register initiates device
operations. Table 1 defines the valid register command
sequences. Writing incorrect address and data values or
writing them in the improper sequence resets the device
to reading array data. Section has details on erasing a
sector or the entire chip, or suspending/resuming the erase
operation.
After the system writes the Automatic Select command
sequence, the device enters the Automatic Select mode.
The system can then read Automatic Select codes from
the internal register (which is separate from the memory
array) on Q7-Q0. Standard read cycle timings apply in
this mode. Refer to the Automatic Select Mode and Au-
tomatic Select Command Sequence section for more in-
formation.
ICC2 in the DC Characteristics table represents the ac-
tive current specification for the write mode. The "AC
Characteristics" section contains timing specification table
and timing diagrams for write operations.
WRITE BUFFER
Write Buffer Programming allows the system to write a
maximum of 16 words/32 bytes in one programming op-
eration. This results in faster effective programming time
than the standard programming algorithms. See "Write
Buffer" for more information.
ACCELERATED PROGRAM OPERATION
The device offers accelerated program operations through
the ACC function. This is one of two functions provided
by the ACC pin. This function is primarily intended to
allow faster manufacturing throughput at the factory.
If the system asserts VHH on this pin, the device auto-
matically enters the aforementioned Unlock Bypass mode,
temporarily unprotects any protected sectors, and uses
the higher voltage on the pin to reduce the time required
for program operations. The system would use a two-cycle
program command sequence as required by the Unlock
Bypass mode. Removing VHH from the ACC
pin must not be at VHH for operations other than acceler-
ated programming, or device damage may result.
MX29LV320MT/B
REV. 1.1 , JUL. 14, 2005
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