参数资料
型号: AM29LV004BB-120EC
厂商: ADVANCED MICRO DEVICES INC
元件分类: PROM
英文描述: 4 Megabit (512 K x 8-Bit) CMOS 3.0 Volt-only Boot Sector Flash Memory
中文描述: 512K X 8 FLASH 3V PROM, 120 ns, PDSO40
封装: MO-142CD, TSOP-40
文件页数: 15/40页
文件大小: 769K
代理商: AM29LV004BB-120EC
14
Am29LV004B
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
sequence 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
sequence cycles in a program command sequence
before programming begins. This resets the device to
reading array data (also applies to programming in
Erase Suspend mode). Once programming begins,
however, the device ignores reset commands until the
operation is complete.
The reset command may be written between the
sequence cycles in an autoselect command sequence.
Once in the autoselect mode, the reset command
must
be written to return to reading array data (also applies
to autoselect during Erase Suspend).
If DQ5 goes high during a program or erase operation,
writing the reset command returns the device to
reading array data (also applies during Erase
Suspend).
Autoselect Command Sequence
The autoselect command sequence allows the host
system to access the manufacturer and devices codes,
and determine whether or not a sector is protected.
Table 5 shows the address and data requirements. This
method is an alternative to that shown in Table 4, which
is intended for PROM programmers and requires V
ID
on address bit A9.
The autoselect command sequence is initiated by
writing two unlock cycles, followed by the autoselect
command. The device then enters the autoselect
mode, and the system may read at any address any
number of times, without initiating another command
sequence. A read cycle at address 00h retrieves the
manufacturer code. A read cycle at address 01h
returns the device code. A read cycle containing a
sector address (SA) and the address 02h returns 01h if
that sector is protected, or 00h if it is unprotected. Refer
to Tables 2 and 3 for valid sector addresses.
The system must write the reset command to exit the
autoselect mode and return to reading array data.
Byte Program Command Sequence
The byte program command sequence programs one
byte into the device. Programming is a four-bus-cycle
operation. The program command sequence is initi-
ated 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
not
required to provide further controls or timings. The
device automatically provides internally generated
program pulses and verify the programmed cell margin.
Table 5 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
DQ7, DQ6, or RY/BY#. See “Write Operation Status”
for information on these status bits.
Any commands written to the device during the
Embedded Program Algorithm are ignored. Note that a
hardware reset
immediately terminates the program-
ming operation. The Byte 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 and across
sector boundaries.
A bit cannot be programmed
from a “0” back to a “1”.
Attempting to do so may halt
the operation and set DQ5 to “1”, or cause the Data#
Polling algorithm to indicate the operation was suc-
cessful. However, a succeeding read will show that the
data is still “0”. Only erase operations can convert a “0”
to a “1”.
Unlock Bypass Command Sequence
The unlock bypass feature allows the system to
program bytes to the device faster than using the stan-
dard program command sequence. The unlock bypass
command sequence is initiated by first writing two
unlock cycles. This is followed by a third write cycle
containing the unlock bypass command, 20h. The
device then enters the unlock bypass mode. A two-
cycle unlock bypass program command sequence is all
that is required to program in this mode. The first cycle
in this sequence contains the unlock bypass program
command, A0h; the second cycle contains the program
address and data. Additional data is programmed in
the same manner. This mode dispenses with the initial
two unlock cycles required in the standard program
command sequence, resulting in faster total program-
ming time. Table 5 shows the requirements for the
command sequence.
During the unlock bypass mode, only the Unlock
Bypass Program and Unlock Bypass Reset commands
are valid. To exit the unlock bypass mode, the system
must issue the two-cycle unlock bypass reset
command sequence. The first cycle must contain the
data 90h; the second cycle the data 00h. The device
then returns to reading array data.
Figure 3 illustrates the algorithm for the program oper-
ation. See the Erase/Program Operations table in “AC
相关PDF资料
PDF描述
AM29LV004BB-120EE 4 Megabit (512 K x 8-Bit) CMOS 3.0 Volt-only Boot Sector Flash Memory
AM29LV004BB-120EI 4 Megabit (512 K x 8-Bit) CMOS 3.0 Volt-only Boot Sector Flash Memory
AM29LV004BB-120FC 4 Megabit (512 K x 8-Bit) CMOS 3.0 Volt-only Boot Sector Flash Memory
AM29LV004BB-120FE 4 Megabit (512 K x 8-Bit) CMOS 3.0 Volt-only Boot Sector Flash Memory
AM29LV004BB-120FI 4 Megabit (512 K x 8-Bit) CMOS 3.0 Volt-only Boot Sector Flash Memory
相关代理商/技术参数
参数描述
AM29LV004BB-120EI 制造商:Rochester Electronics LLC 功能描述: 制造商:Advanced Micro Devices 功能描述:NOR Flash, 512K x 8, 40 Pin, Plastic, TSSOP
AM29LV004BB120EI\T 制造商:Advanced Micro Devices 功能描述:4 Mb (512K x 8) Boot Sector, Flash Memory
AM29LV004BB-120EIT 制造商:Rochester Electronics LLC 功能描述: 制造商:Advanced Micro Devices 功能描述:
am29lv004bt-120ed 制造商:Advanced Micro Devices 功能描述:
AM29LV004BT-90EI 制造商:Advanced Micro Devices 功能描述: