A29L004UW-70 AMICC [AMIC Technology], A29L004UW-70 Datasheet - Page 12

• Manufacturer Part Number: A29L004UW-70
• Description: 512K X 8 Bit CMOS 3.0 Volt-only, Boot Sector Flash Memory
• Manufacturer: AMICC [AMIC Technology]

Command Definitions
Writing specific address and data commands or sequences
into the command register initiates device operations. The
Command Definitions table 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.
All addresses are latched on the falling edge of
whichever happens later. All data is latched on the rising edge
of
appropriate timing diagrams in the "AC Characteristics"
section.
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 Embedded Program or Embedded Erase algorithm. After
the device accepts an Erase Suspend command, the device
enters the Erase Suspend mode. The system can read array
data using the standard read timings, except that if it reads at
an address within erase-suspended sectors, the device
outputs status data. After completing a programming
operation in the Erase Suspend mode, the system may once
again read array data with the same exception. See "Erase
Suspend/Erase Resume Commands" for more information on
this mode.
The system must issue the reset command to re-enable the
device for reading array data if I/O
autoselect mode. See the "Reset Command" section, next.
See also "Requirements for Reading Array Data" in the
"Device Bus Operations" section for more information. The
Read Operations table provides the read parameters, and
Read Operation Timings diagram shows the timing diagram.
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 I/O
the reset command returns the device to reading array data
(also applies during Erase Suspend).
PRELIMINARY
WE
5
goes high during a program or erase operation, writing
or
CE
, whichever happens first. Refer to the
(October, 2002, Version 0.0)
5
goes high, or while in the
WE
or
CE
,
12
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. The Command Definitions
table shows the address and data requirements. This method
is an alternative to that shown in the Autoselect Codes (High
Voltage Method) table, which is intended for PROM
programmers and requires V
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 XX00h retrieves the manufacturer
code and another read cycle at XX03h retrieves the
continuation code. A read cycle at address XX01h returns the
device code. A read cycle containing a sector address (SA)
and the address 02h in returns 01h if that sector is protected,
or 00h if it is unprotected. Refer to the Sector Address tables
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
Programming is a four-bus-cycle operation. The program
command sequence 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 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
longer latched. The system can determine the status of the
program operation by using I/O
PLCC & (s)TSOP packages). 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 programming 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 I/O5 to
“1”, or 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”.
AMIC Technology, Corp.
ID
A29L004 Series
on address bit A9.
7
, I/O
6
, or RY/ BY (N/A on 32-pin