AMD AM29F400BT-55EE 4 megabit (512 k x 8-bit/256 k x 16-bit) cmos 5.0 volt-only boot sector flash memory Datasheet

PRELIMINARY
Am29F400B
4 Megabit (512 K x 8-Bit/256 K x 16-Bit)
CMOS 5.0 Volt-only Boot Sector Flash Memory
DISTINCTIVE CHARACTERISTICS
■ Single power supply operation
— 5.0 volt-only operation for read, erase, and
program operations
— Minimizes system level requirements
■ Manufactured on 0.35 µm process technology
— Compatible with 0.5 µm Am29F400 device
■ High performance
— Access times as fast as 55 ns
■ Low power consumption (typical values at 5
MHz)
■ Top or bottom boot block configurations
available
■ Embedded Algorithms
— Embedded Erase algorithm automatically
preprograms and erases the entire chip or any
combination of designated sectors
— Embedded Program algorithm automatically
writes and verifies data at specified addresses
■ Minimum 1,000,000 program/erase cycles per
sector guaranteed
■ Package option
— 1 µA standby mode current
— 48-pin TSOP
— 20 mA read current (byte mode)
— 44-pin SO
— 28 mA read current (word mode)
— 30 mA program/erase current
■ Flexible sector architecture
— One 16 Kbyte, two 8 Kbyte, one 32 Kbyte, and
seven 64 Kbyte sectors (byte mode)
— One 8 Kword, two 4 Kword, one 16 Kword, and
seven 32 Kword sectors (word mode)
— Supports full chip erase
— Sector Protection features:
A hardware method of locking a sector to
prevent any program or erase operations within
that sector
Sectors can be locked via programming
equipment
Temporary Sector Unprotect feature allows code
changes in previously locked sectors
■ Compatibility with JEDEC standards
— Pinout and software compatible with singlepower-supply Flash
— Superior inadvertent write protection
■ Data# Polling and toggle bits
— Provides a software method of detecting
program or erase operation completion
■ Ready/Busy# pin (RY/BY#)
— Provides a hardware method of detecting
program or erase cycle completion
■ Erase Suspend/Erase Resume
— Suspends an erase operation to read data from,
or program data to, a sector that is not being
erased, then resumes the erase operation
■ Hardware reset pin (RESET#)
— Hardware method to reset the device to reading
array data
Publication# 21505 Rev: C Amendment/+2
Issue Date: April 1998
PRELIMINARY
GENERAL DESCRIPTION
The Am29F400B is a 4 Mbit, 5.0 volt-only Flash
memory organized as 524,288 bytes or 262,144 words.
The device is offered in 44-pin SO and 48-pin TSOP
packages. The word-wide data (x16) appears on
DQ15–DQ0; the byte-wide (x8) data appears on DQ7–
DQ0. This device is designed to be programmed insystem with the standard system 5.0 volt VCC supply.
A 12.0 V VPP is not required for write or erase operations. The device can also be programmed in standard
EPROM programmers.
This device is manufactured using AMD’s 0.35 µm
process technology, and offers all the features and benefits of the Am29F400, which was manufactured using
0.5 µm process technology.
The standard device offers access times of 55, 60, 70,
90, 120, and 150 ns, allowing high speed microprocessors to operate without wait states. To eliminate bus
contention the device has separate chip enable (CE#),
write enable (WE#) and output enable (OE#) controls.
The device requires only a single 5.0 volt power supply for both read and write functions. Internally generated and regulated voltages are provided for the
program and erase operations.
The device is entirely command set compatible with the
JEDEC single-power-supply Flash standard. Commands are written to the command register using
standard microprocessor write timings. Register contents serve as input to an internal state-machine that
controls the erase and programming circuitry. Write
cycles also internally latch addresses and data needed
for the programming and erase operations. Reading
data out of the device is similar to reading from other
Flash or EPROM devices.
Device programming occurs by executing the program
command sequence. This initiates the Embedded
Program algorithm—an internal algorithm that automatically times the program pulse widths and verifies
proper cell margin.
Device erasure occurs by executing the erase command sequence. This initiates the Embedded Erase
2
algorithm—an internal algorithm that automatically
preprograms the array (if it is not already programmed) before executing the erase operation. During erase, the device automatically times the erase
pulse widths and verifies proper cell margin.
The host system can detect whether a program or
erase operation is complete by observing the RY/BY#
pin, or by reading the DQ7 (Data# Polling) and
DQ6/DQ2 (toggle) status bits. After a program or
erase cycle has been completed, the device is ready to
read array data or accept another command.
The sector erase architecture allows memory sectors
to be erased and reprogrammed without affecting the
data contents of other sectors. The device is fully
erased when shipped from the factory.
Hardware data protection measures include a low
VCC detector that automatically inhibits write operations during power transitions. The hardware sector
protection feature disables both program and erase
operations in any combination of the sectors of memory. This can be achieved via programming equipment.
The Erase Suspend feature enables the user to put
erase on hold for any period of time to read data from,
or program data to, any sector that is not selected for
erasure. True background erase can thus be achieved.
The hardware RESET# pin terminates any operation
in progress and resets the internal state machine to
reading array data. The RESET# pin may be tied to the
system reset circuitry. A system reset would thus also
reset the device, enabling the system microprocessor
to read the boot-up firmware from the Flash memory.
The system can place the device into the standby mode.
Power consumption is greatly reduced in this mode.
AMD’s Flash technology combines years of Flash
memory manufacturing experience to produce the
highest levels of quality, reliability and cost effectiveness.
The device electrically erases all bits within a sector
simultaneously via Fowler-Nordheim tunneling. The
data is programmed using hot electron injection.
Am29F400B
PRELIMINARY
PRODUCT SELECTOR GUIDE
Family Part Number
Speed Option
Am29F400B
VCC = 5.0 V ± 5%
-55
VCC = 5.0 V ± 10%
-60
-70
-90
-120
-150
Max access time, ns (tACC)
55
60
70
90
120
150
Max CE# access time, ns (tCE)
55
60
70
90
120
150
Max OE# access time, ns (tOE)
30
30
30
35
50
55
Note: See “AC Characteristics” for full specifications.
BLOCK DIAGRAM
DQ0–DQ15 (A-1)
RY/BY#
VCC
Sector Switches
VSS
Erase Voltage
Generator
RESET#
WE#
BYTE#
Input/Output
Buffers
State
Control
Command
Register
PGM Voltage
Generator
Chip Enable
Output Enable
Logic
CE#
OE#
VCC Detector
Address Latch
STB
Timer
A0–A17
STB
Data
Latch
Y-Decoder
Y-Gating
X-Decoder
Cell Matrix
21505C-1
Am29F400B
3
PRELIMINARY
CONNECTION DIAGRAMS
A15
A14
A13
A12
A11
A10
A9
A8
NC
NC
WE#
RESET#
NC
NC
RY/BY#
NC
A17
A7
A6
A5
A4
A3
A2
A1
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
48
47
46
45
44
43
42
41
40
39
38
37
36
35
34
33
32
31
30
29
28
27
26
25
A16
BYTE#
VSS
DQ15/A-1
DQ7
DQ14
DQ6
DQ13
DQ5
DQ12
DQ4
VCC
DQ11
DQ3
DQ10
DQ2
DQ9
DQ1
DQ8
DQ0
OE#
VSS
CE#
A0
48
47
46
45
44
43
42
41
40
39
38
37
36
35
34
33
32
31
30
29
28
27
26
25
A15
A14
A13
A12
A11
A10
A9
A8
NC
NC
WE#
RESET#
NC
NC
RY/BY#
NC
A17
A7
A6
A5
A4
A3
A2
A1
48-Pin TSOP—Standard Pinout
A16
BYTE#
VSS
DQ15/A-1
DQ7
DQ14
DQ6
DQ13
DQ5
DQ12
DQ4
VCC
DQ11
DQ3
DQ10
DQ2
DQ9
DQ1
DQ8
DQ0
OE#
VSS
CE#
A0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
48-Pin TSOP—Reverse Pinout
21505C-2
4
Am29F400B
PRELIMINARY
CONNECTION DIAGRAMS
SO
NC
RY/BY#
A17
A7
A6
A5
A4
A3
A2
A1
A0
CE#
VSS
OE#
DQ0
DQ8
DQ1
DQ9
DQ2
DQ10
DQ3
DQ11
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
44
43
42
41
40
39
38
37
36
35
34
33
32
31
30
29
28
27
26
25
24
23
RESET#
WE#
A8
A9
A10
A11
A12
A13
A14
A15
A16
BYTE#
VSS
DQ15/A-1
DQ7
DQ14
DQ6
DQ13
DQ5
DQ12
DQ4
VCC
21505C-3
PIN CONFIGURATION
A0–A17
LOGIC SYMBOL
= 18 addresses
18
DQ0–DQ14 = 15 data inputs/outputs
A0–A17
DQ15/A-1
= DQ15 (data input/output, word mode),
A-1 (LSB address input, byte mode)
BYTE#
= Selects 8-bit or 16-bit mode
CE#
= Chip enable
OE#
= Output enable
WE#
= Write enable
RESET#
RESET#
= Hardware reset pin, active low
BYTE#
RY/BY#
= Ready/Busy# output
VCC
= +5.0 V single power supply
(see Product Selector Guide for
device speed ratings and voltage
supply tolerances)
VSS
= Device ground
NC
= Pin not connected internally
16 or 8
DQ0–DQ15
(A-1)
CE#
OE#
WE#
RY/BY#
21505C-4
Am29F400B
5
PRELIMINARY
ORDERING INFORMATION
Standard Products
AMD standard products are available in several packages and operating ranges. The order number (Valid Combination) is formed
by a combination of the elements below.
Am29F400B
T
-55
E
C
OPTIONAL PROCESSING
Blank = Standard Processing
B = Burn-in
(Contact an AMD representative for more information)
TEMPERATURE RANGE
C = Commercial (0°C to +70°C)
I = Industrial (–40°C to +85°C)
E = Extended (–55°C to +125°C)
PACKAGE TYPE
E
= 48-Pin Thin Small Outline Package (TSOP)
Standard Pinout (TS 048)
F
= 48-Pin Thin Small Outline Package (TSOP)
Reverse Pinout (TSR048)
S
= 44-Pin Small Outline Package (SO 044)
SPEED OPTION
See Product Selector Guide and Valid Combinations
BOOT CODE SECTOR ARCHITECTURE
T = Top Sector
B = Bottom Sector
DEVICE NUMBER/DESCRIPTION
Am29F400B
4 Megabit (512 K x 8-Bit/256 K x 16-Bit) CMOS Flash Memory
5.0 Volt-only Read, Program, and Erase
Valid Combinations
Valid Combinations
Am29F400BT-55,
Am29F400BB-55
EC, EI, FC, FI, SC, SI
Am29F400BT-60,
Am29F400BB-60
Valid Combinations list configurations planned to be supported in volume for this device. Consult the local AMD sales
office to confirm availability of specific valid combinations and
to check on newly released combinations.
Am29F400BT-70,
Am29F400BB-70
Am29F400BT-90,
Am29F400BB-90
EC, EI, EE,
FC, FI, FE,
SC, SI, SE
Am29F400BT-120,
Am29F400BB-120
Am29F400BT-150,
Am29F400BB-150
6
Am29F400B
PRELIMINARY
DEVICE BUS OPERATIONS
This section describes the requirements and use of the
device bus operations, which are initiated through the
internal command register. The command register itself does not occupy any addressable memory location. The register is composed of latches that store the
commands, along with the address and data information needed to execute the command. The contents of
Table 1.
the register serve as inputs to the internal state machine. The state machine outputs dictate the function of
the device. Table 1 lists the device bus operations, the
inputs and control levels they require, and the resulting
output. The following subsections describe each of
these operations in further detail.
Am29F400B Device Bus Operations
DQ8–DQ15
Operation
CE#
OE#
WE#
RESET#
A0–A17
DQ0–DQ7
BYTE#
= VIH
L
L
H
H
AIN
DOUT
DOUT
High-Z
L
H
L
H
AIN
DIN
DIN
High-Z
X
High-Z
High-Z
High-Z
X
High-Z
High-Z
High-Z
Read
Write
BYTE#
= VIL
VCC ±
0.5 V
X
X
VCC ±
0.5 V
H
X
X
H
Output Disable
L
H
H
H
X
High-Z
High-Z
High-Z
Hardware Reset
X
X
X
L
X
High-Z
High-Z
High-Z
Temporary Sector Unprotect
(See Note)
X
X
X
VID
AIN
DIN
DIN
High-Z
CMOS Standby
TTL Standby
Legend:
L = Logic Low = VIL, H = Logic High = VIH, VID = 12.0 ± 0.5 V, X = Don’t Care, DIN = Data In, DOUT = Data Out, AIN = Address In
Note: See the sections on Sector Protection and Temporary Sector Unprotect for more information.
Word/Byte Configuration
The BYTE# pin controls whether the device data I/O
pins DQ15–DQ0 operate in the byte or word configuration. If the BYTE# pin is set at logic ‘1’, the device is in
word configuration, DQ15–DQ0 are active and controlled by CE# and OE#.
If the BYTE# pin is set at logic ‘0’, the device is in byte
configuration, and only data I/O pins DQ0–DQ7 are active and controlled by CE# and OE#. The data I/O pins
DQ8–DQ14 are tri-stated, and the DQ15 pin is used as
an input for the LSB (A-1) address function.
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
remain at VIH. The BYTE# pin determines whether the
device outputs array data in words or bytes.
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 content occurs during the power transition. No command is
necessary in this mode to obtain array data. Standard
microprocessor read cycles that assert valid addresses
on the device address inputs produce valid data on the
device data outputs. The device remains enabled for
read access until the command register contents are
altered.
See “Reading Array Data” for more information. Refer
to the AC Read Operations table for timing specifications and to Figure 9 for the timing diagram. ICC1 in the
DC Characteristics table represents the active current
specification for reading array data.
Writing Commands/Command Sequences
To write a command or command sequence (which includes programming data to the device and erasing
sectors of memory), the system must drive WE# and
CE# to VIL, and OE# to VIH.
For program operations, the BYTE# pin determines
whether the device accepts program data in bytes or
words. Refer to “Word/Byte Configuration” for more information.
An erase operation can erase one sector, multiple sectors, or the entire device. Tables 2 and 3 indicate the
address space that each sector occupies. A “sector address” consists of the address bits required to uniquely
select a sector. The “Command Definitions” section
has details on erasing a sector or the entire chip, or
suspending/resuming the erase operation.
Am29F400B
7
PRELIMINARY
After the system writes the autoselect command sequence, the device enters the autoselect mode. The
system can then read autoselect codes from the internal register (which is separate from the memory array)
on DQ7–DQ0. Standard read cycle timings apply in this
mode. Refer to the “Autoselect Mode” and “Autoselect
Command Sequence” sections for more information.
ICC2 in the DC Characteristics table represents the active current specification for the write mode. The “AC
Characteristics” section contains timing specification
tables and timing diagrams for write operations.
Program and Erase Operation Status
During an erase or program operation, the system may
check the status of the operation by reading the status
bits on DQ7–DQ0. Standard read cycle timings and ICC
read specifications apply. Refer to “Write Operation
Status” for more information, and to “AC Characteristics” for timing diagrams.
Standby Mode
When the system is not reading or writing to the device,
it can place the device in the standby mode. In this
mode, current consumption is greatly reduced, and the
outputs are placed in the high impedance state, independent of the OE# input.
The device enters the CMOS standby mode when the
CE# and RESET# pins are both held at VCC ± 0.5 V.
(Note that this is a more restricted voltage range than
VIH.) The device enters the TTL standby mode when
CE# and RESET# pins are both held at VIH. The device
requires standard access time (tCE) for read access
when the device is in either of these standby modes,
before it is ready to read data.
The device also enters the standby mode when the RESET# pin is driven low. Refer to the next section, “RESET#: Hardware Reset Pin”.
If the device is deselected during erasure or programming, the device draws active current until the
operation is completed.
8
In the CMOS and TTL/NMOS-compatible DC Characteristics tables, ICC3 represents the standby current
specification.
RESET#: Hardware Reset Pin
The RESET# pin provides a hardware method of resetting the device to reading array data. When the RESET# pin is driven low for at least a period of tRP, the
device immediately terminates any operation in
progress, tristates all output pins, and ignores all
read/write commands for the duration of the RESET#
pulse. The device also resets the internal state machine to reading array data. The operation that was interrupted should be reinitiated once the device is ready
to accept another command sequence, to ensure data
integrity.
Current is reduced for the duration of the RESET#
pulse. When RESET# is held at VIL, the device enters
the TTL standby mode; if RESET# is held at VSS±0.5
V, the device enters the CMOS standby mode.
The RESET# pin may be tied to the system reset circuitry. A system reset would thus also reset the Flash
memory, enabling the system to read the boot-up
firmware from the Flash memory.
If RESET# is asserted during a program or erase operation, the RY/BY# pin remains a “0” (busy) until the internal reset operation is complete, which requires a
time of tREADY (during Embedded Algorithms). The
system can thus monitor RY/BY# to determine whether
the reset operation is complete. If RESET# is asserted
when a program or erase operation is not executing
(RY/BY# pin is “1”), the reset operation is completed
within a time of tREADY (not during Embedded Algorithms). The system can read data tRH after the RESET# pin returns to VIH.
Refer to the AC Characteristics tables for RESET# parameters and to Figure 10 for the timing diagram.
Output Disable Mode
When the OE# input is at VIH, output from the device is
disabled. The output pins are placed in the high impedance state.
Am29F400B
PRELIMINARY
Table 2.
Am29F400BT Top Boot Block Sector Address Table
Address Range (in hexadecimal)
Sector
A17
A16
A15
A14
A13
A12
Sector Size
(Kbytes/
Kwords)
SA0
0
0
0
X
X
X
64/32
00000h–0FFFFh
00000h–07FFFh
SA1
0
0
1
X
X
X
64/32
10000h–1FFFFh
08000h–0FFFFh
SA2
0
1
0
X
X
X
64/32
20000h–2FFFFh
10000h–17FFFh
SA3
0
1
1
X
X
X
64/32
30000h–3FFFFh
18000h–1FFFFh
SA4
1
0
0
X
X
X
64/32
40000h–4FFFFh
20000h–27FFFh
SA5
1
0
1
X
X
X
64/32
50000h–5FFFFh
28000h–2FFFFh
SA6
1
1
0
X
X
X
64/32
60000h–6FFFFh
30000h–37FFFh
SA7
1
1
1
0
X
X
32/16
70000h–77FFFh
38000h–3BFFFh
SA8
1
1
1
1
0
0
8/4
78000h–79FFFh
3C000h–3CFFFh
(x8)
Address Range
(x16)
Address Range
SA9
1
1
1
1
0
1
8/4
7A000h–7BFFFh
3D000h–3DFFFh
SA10
1
1
1
1
1
X
16/8
7C000h–7FFFFh
3E000h–3FFFFh
Table 3.
Am29F400BB Bottom Boot Block Sector Address Table
Address Range (in hexadecimal)
Sector
A17
A16
A15
A14
A13
A12
Sector Size
(Kbytes/
Kwords)
SA0
0
0
0
0
0
X
16/8
00000h–03FFFh
00000h–01FFFh
SA1
0
0
0
0
1
0
8/4
04000h–05FFFh
02000h–02FFFh
SA2
0
0
0
0
1
1
8/4
06000h–07FFFh
03000h–03FFFh
SA3
0
0
0
1
X
X
32/16
08000h–0FFFFh
04000h–07FFFh
SA4
0
0
1
X
X
X
64/32
10000h–1FFFFh
08000h–0FFFFh
SA5
0
1
0
X
X
X
64/32
20000h–2FFFFh
10000h–17FFFh
SA6
0
1
1
X
X
X
64/32
30000h–3FFFFh
18000h–1FFFFh
SA7
1
0
0
X
X
X
64/32
40000h–4FFFFh
20000h–27FFFh
SA8
1
0
1
X
X
X
64/32
50000h–5FFFFh
28000h–2FFFFh
(x8)
Address Range
(x16)
Address Range
SA9
1
1
0
X
X
X
64/32
60000h–6FFFFh
30000h–37FFFh
SA10
1
1
1
X
X
X
64/32
70000h–7FFFFh
38000h–3FFFFh
Note:
Address range is A17:A-1 in byte mode and A17:A0 in word mode. See “Word/Byte Configuration” section for more information.
Autoselect Mode
The autoselect mode provides manufacturer and device identification, and sector protection verification,
through identifier codes output on DQ7–DQ0. This
mode is primarily intended for programming equipment
to automatically match a device to be programmed with
its corresponding programming algorithm. However,
the autoselect codes can also be accessed in-system
through the command register.
When using programming equipment, the autoselect
mode requires VID (11.5 V to 12.5 V) on address pin
A9. Address pins A6, A1, and A0 must be as shown in
Table 4. In addition, when verifying sector protection,
the sector address must appear on the appropriate
highest order address bits (see Tables 2 and 3). Table
4 shows the remaining address bits that are don’t care.
When all necessary bits have been set as required, the
programming equipment may then read the corresponding identifier code on DQ7–DQ0.
To access the autoselect codes in-system, the host
system can issue the autoselect command via the
command register, as shown in Table 5. This method
does not require VID. See “Command Definitions” for
details on using the autoselect mode.
Am29F400B
9
PRELIMINARY
Table 4.
Description
Mode
Am29F400B Autoselect Codes (High Voltage Method)
A17 A11
to
to
WE# A12 A10
CE#
OE#
Manufacturer ID: AMD
L
L
H
Device ID:
Am29F400B
(Top Boot Block)
Word
L
L
H
Byte
L
L
H
Device ID:
Am29F400B
(Bottom Boot Block)
Word
L
L
H
Sector Protection Verification
L
L
L
L
A1
A0
DQ8
to
DQ15
DQ7
to
DQ0
X
01h
22h
23h
X
23h
22h
ABh
X
ABh
X
01h
(protected)
X
00h
(unprotected)
X
VID
X
L
X
L
L
X
X
VID
X
L
X
L
H
VID
X
X
H
H
A6
A5
to
A2
X
X
Byte
A9
A8
to
A7
SA
X
VID
X
L
L
X
X
L
H
H
L
L = Logic Low = VIL, H = Logic High = VIH, SA = Sector Address, X = Don’t care.
Sector Protection/Unprotection
The hardware sector protection feature disables both program and erase operations in any sector. The hardware
sector unprotection feature re-enables both program and
erase operations in previously protected sectors.
START
RESET# = VID
(Note 1)
Sector protection/unprotection must be implemented
using programming equipment. The procedure requires a high voltage (VID) on address pin A9 and OE#.
Details on this method are provided in a supplement,
publication number 20185. Contact an AMD representative to obtain a copy of this document.
Perform Erase or
Program Operations
RESET# = VIH
The device is shipped with all sectors unprotected.
AMD offers the option of programming and protecting
sectors at its factory prior to shipping the device
through AMD’s ExpressFlash™ Service. Contact an
AMD representative for details.
Temporary Sector
Unprotect Completed
(Note 2)
It is possible to determine whether a sector is protected
or unprotected. See “Autoselect Mode” for details.
21505C-5
Temporary Sector Unprotect
This feature allows temporary unprotection of previously protected sectors to change data in-system. The
Sector Unprotect mode is activated by setting the RESET# pin to VID. During this mode, formerly protected
sectors can be programmed or erased by selecting the
sector addresses. Once VID is removed from the RESET# pin, all the previously protected sectors are
protected again. Figure 1 shows the algorithm, and
Figure 18 shows the timing diagrams, for this feature.
10
Notes:
1. All protected sectors unprotected.
2. All previously protected sectors are protected once
again.
Figure 1.
Temporary Sector Unprotect Operation
Hardware Data Protection
The command sequence requirement of unlock cycles
for programming or erasing provides data protection
against inadvertent writes (refer to Table 5 for command definitions). In addition, the following hardware
data protection measures prevent accidental erasure
or programming, which might otherwise be caused by
Am29F400B
PRELIMINARY
spurious system level signals during VCC power-up and
power-down transitions, or from system noise.
Low VCC Write Inhibit
When VCC is less than VLKO, the device does not accept any write cycles. This protects data during VCC
power-up and power-down. The command register and
all internal program/erase circuits are disabled, and the
device resets. Subsequent writes are ignored until VCC
is greater than V LKO. The system must provide the
proper signals to the control pins to prevent unintentional writes when VCC is greater than VLKO.
Write Pulse “Glitch” Protection
Noise pulses of less than 5 ns (typical) on OE#, CE# or
WE# do not initiate a write cycle.
Logical Inhibit
Write cycles are inhibited by holding any one of OE# =
VIL, CE# = VIH or WE# = VIH. To initiate a write cycle,
CE# and WE# must be a logical zero while OE# is a
logical one.
Power-Up Write Inhibit
If WE# = CE# = VIL and OE# = VIH during power up, the
device does not accept commands on the rising edge
of WE#. The internal state machine is automatically
reset to reading array data on power-up.
COMMAND DEFINITIONS
Writing specific address and data commands or sequences into the command register initiates device operations. Table 5 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 WE# or
CE#, whichever happens later. All data is latched on
the rising edge of WE# or CE#, whichever happens
first. Refer to the 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 erasesuspended 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 DQ5 goes high,
or while in the 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 Figure 9 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 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 VID
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
Am29F400B
11
PRELIMINARY
number of times, without initiating another command
sequence.
START
A read cycle at address XX00h or retrieves the manufacturer code. A read cycle at address XX01h in word
mode (or 02h in byte mode) returns the device code.
A read cycle containing a sector address (SA) and the
address 02h in word mode (or 04h in byte mode) returns 01h if that sector is protected, or 00h if it is unprotected. Refer to Tables 2 and 3 for valid sector
addresses.
Write Program
Command Sequence
The system must write the reset command to exit the
autoselect mode and return to reading array data.
Embedded
Program
algorithm
in progress
Word/Byte Program Command Sequence
The system may program the device by word or byte,
depending on the state of the BYTE# pin. 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 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 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 DQ5 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”.
Data Poll
from System
Verify Data?
No
Yes
Increment Address
No
Last Address?
Yes
Programming
Completed
21505C-6
Note:
See Table 5 for program command sequence.
Figure 2.
Program Operation
Chip Erase Command Sequence
Chip erase is a six-bus-cycle operation. The chip erase
command sequence is initiated by writing two unlock
cycles, followed by a set-up command. Two additional
unlock write cycles are then followed by the chip erase
command, which in turn invokes the Embedded Erase
algorithm. The device does not require the system to
preprogram prior to erase. The Embedded Erase algorithm automatically preprograms and verifies the entire
memory for an all zero data pattern prior to electrical
erase. The system is not required to provide any controls or timings during these operations. Table 5 shows
the address and data requirements for the chip erase
command sequence.
Any commands written to the chip during the Embedded Erase algorithm are ignored. Note that a hardware
reset during the chip erase operation immediately terminates the operation. The Chip Erase command sequence should be reinitiated once the device has
returned to reading array data, to ensure data integrity.
12
Am29F400B
PRELIMINARY
The system can determine the status of the erase operation by using DQ7, DQ6, DQ2, or RY/BY#. See
“Write Operation Status” for information on these status bits. When the Embedded Erase algorithm is complete, the device returns to reading array data and
addresses are no longer latched.
When the Embedded Erase algorithm is complete, the
device returns to reading array data and addresses are
no longer latched. The system can determine the status of the erase operation by using DQ7, DQ6, DQ2, or
RY/BY#. (Refer to “Write Operation Status” for information on these status bits.)
Figure 3 illustrates the algorithm for the erase operation. See the “Erase/Program Operations” tables in “AC
Characteristics” for parameters, and to Figure 14 for
timing diagrams.
Figure 3 illustrates the algorithm for the erase operation. Refer to the “Erase/Program Operations” tables in
the “AC Characteristics” section for parameters, and to
Figure 14 for timing diagrams.
Sector Erase Command Sequence
Erase Suspend/Erase Resume Commands
Sector erase is a six bus cycle operation. The sector
erase command sequence is initiated by writing two unlock cycles, followed by a set-up command. Two additional unlock write cycles are then followed by the
address of the sector to be erased, and the sector
erase command. Table 5 shows the address and data
requirements for the sector erase command sequence.
The Erase Suspend command allows the system to interrupt a sector erase operation and then read data
from, or program data to, any sector not selected for
erasure. This command is valid only during the sector
erase operation, including the 50 µs time-out period
during the sector erase command sequence. The
Erase Suspend command is ignored if written during
the chip erase operation or Embedded Program algorithm. Writing the Erase Suspend command during the
Sector Erase time-out immediately terminates the
time-out period and suspends the erase operation. Addresses are “don’t-cares” when writing the Erase Suspend command.
The device does not require the system to preprogram
the memory prior to erase. The Embedded Erase algorithm automatically programs and verifies the sector for
an all zero data pattern prior to electrical erase. The
system is not required to provide any controls or timings during these operations.
After the command sequence is written, a sector erase
time-out of 50 µs begins. During the time-out period,
additional sector addresses and sector erase commands may be written. Loading the sector erase buffer
may be done in any sequence, and the number of sectors may be from one sector to all sectors. The time between these additional cycles must be less than 50 µs,
otherwise the last address and command might not be
accepted, and erasure may begin. It is recommended
that processor interrupts be disabled during this time to
ensure all commands are accepted. The interrupts can
be re-enabled after the last Sector Erase command is
written. If the time between additional sector erase
commands can be assumed to be less than 50 µs, the
system need not monitor DQ3. Any command other
than Sector Erase or Erase Suspend during the
time-out period resets the device to reading array
data. The system must rewrite the command sequence
and any additional sector addresses and commands.
The system can monitor DQ3 to determine if the sector
erase timer has timed out. (See the “DQ3: Sector Erase
Timer” section.) The time-out begins from the rising
edge of the final WE# pulse in the command sequence.
Once the sector erase operation has begun, only the
Erase Suspend command is valid. All other commands
are ignored. Note that a hardware reset during the
sector erase operation immediately terminates the operation. The Sector Erase command sequence should
be reinitiated once the device has returned to reading
array data, to ensure data integrity.
When the Erase Suspend command is written during
a sector erase operation, the device requires a maximum of 20 µs to suspend the erase operation. However, when the Erase Suspend command is written
during the sector erase time-out, the device immediately terminates the time-out period and suspends the
erase operation.
After the erase operation has been suspended, the
system can read array data from or program data to
any sector not selected for erasure. (The device “erase
suspends” all sectors selected for erasure.) Normal
read and write timings and command definitions apply.
Reading at any address within erase-suspended sectors produces status data on DQ7–DQ0. The system
can use DQ7, or DQ6 and DQ2 together, to determine
if a sector is actively erasing or is erase-suspended.
See “Write Operation Status” for information on these
status bits.
After an erase-suspended program operation is complete, the system can once again read array data within
non-suspended sectors. The system can determine
the status of the program operation using the DQ7 or
DQ6 status bits, just as in the standard program operation. See “Write Operation Status” for more information.
The system may also write the autoselect command
sequence when the device is in the Erase Suspend
mode. The device allows reading autoselect codes
even at addresses within erasing sectors, since the
codes are not stored in the memory array. When the
Am29F400B
13
PRELIMINARY
device exits the autoselect mode, the device reverts to
the Erase Suspend mode, and is ready for another
valid operation. See “Autoselect Command Sequence”
for more information.
The system must write the Erase Resume command
(address bits are “don’t care”) to exit the erase suspend
mode and continue the sector erase operation. Further
writes of the Resume command are ignored. Another
Erase Suspend command can be written after the device has resumed erasing.
START
Write Erase
Command Sequence
Data Poll
from System
No
Embedded
Erase
algorithm
in progress
Data = FFh?
Yes
Erasure Completed
21505C-7
Notes:
1. See Table 5 for erase command sequence.
2. See “DQ3: Sector Erase Timer” for more information.
Figure 3.
14
Erase Operation
Am29F400B
PRELIMINARY
Table 5.
Am29F400B Command Definitions
Cycles
Bus Cycles (Notes 2–5)
Addr
Data
Read (Note 6)
1
RA
RD
Reset (Note 7)
1
XXX
F0
Command
Sequence
(Note 1)
Autoselect (Note 8)
Manufacturer ID
Word
Byte
Device ID,
Top Boot Block
Word
Device ID,
Bottom Boot Block
Word
Byte
Byte
4
4
4
Word
Sector Protect Verify
(Note 9)
Program
Chip Erase
Sector Erase
First
555
AAA
555
AAA
555
AAA
Second
AA
AA
AA
555
4
Addr
2AA
555
2AA
555
2AA
555
Third
Data
Addr
555
55
AAA
555
55
AAA
555
55
AAA
2AA
AA
55
555
AAA
Word
555
2AA
555
Word
Byte
Word
Byte
6
6
AAA
555
AAA
555
AAA
AA
AA
AA
Erase Suspend (Note 10)
1
XXX
B0
Erase Resume (Note 11)
1
XXX
30
555
2AA
555
2AA
555
90
90
90
55
AAA
555
55
AAA
555
55
AAA
A0
80
80
Data
X00
01
X01
2223
X02
23
X01
22AB
X02
AB
(SA)
X02
XX00
(SA)
X04
00
PA
PD
90
AAA
4
Data Addr
555
Byte
Byte
Fourth
555
AAA
555
AAA
Fifth
Sixth
Addr Data
Addr
Data
XX01
01
AA
AA
2AA
555
2AA
555
55
55
555
AAA
SA
10
30
Legend:
X = Don’t care
PD = Data to be programmed at location PA. Data latches on the
rising edge of WE# or CE# pulse, whichever happens first.
RA = Address of the memory location to be read.
SA = Address of the sector to be verified (in autoselect mode) or
erased. Address bits A17–A12 uniquely select any sector.
RD = Data read from location RA during read operation.
PA = Address of the memory location to be programmed.
Addresses latch on the falling edge of the WE# or CE# pulse,
whichever happens later.
Notes:
1. See Table 1 for description of bus operations.
8. The fourth cycle of the autoselect command sequence is a
read cycle.
2. All values are in hexadecimal.
3. Except when reading array or autoselect data, all bus cycles
are write operations.
4. Data bits DQ15–DQ8 are don’t cares for unlock and
command cycles.
9. The data is 00h for an unprotected sector and 01h for a
protected sector. See “Autoselect Command Sequence” for
more information.
5. Address bits A17–A11 are don’t cares for unlock and
command cycles, unless PA or SA required.
10. The system may read and program in non-erasing sectors, or
enter the autoselect mode, when in the Erase Suspend
mode. The Erase Suspend command is valid only during a
sector erase operation.
6. No unlock or command cycles required when reading array
data.
11. The Erase Resume command is valid only during the Erase
Suspend mode.
7. The Reset command is required to return to reading array
data when device is in the autoselect mode, or if DQ5 goes
high (while the device is providing status data).
Am29F400B
15
PRELIMINARY
WRITE OPERATION STATUS
The device provides several bits to determine the status of a write operation: DQ2, DQ3, DQ5, DQ6, DQ7,
and RY/BY#. Table 6 and the following subsections describe the functions of these bits. DQ7, RY/BY#, and
DQ6 each offer a method for determining whether a
program or erase operation is complete or in progress.
These three bits are discussed first.
START
Read DQ7–DQ0
Addr = VA
DQ7: Data# Polling
The Data# Polling bit, DQ7, indicates to the host system whether an Embedded Algorithm is in progress
or completed, or whether the device is in Erase Suspend. Data# Polling is valid after the rising edge of
the final WE# pulse in the program or erase command sequence.
During the Embedded Program algorithm, the device
outputs on DQ7 the complement of the datum programmed to DQ7. This DQ7 status also applies to programming during Erase Suspend. When the
Embedded Program algorithm is complete, the device
outputs the datum programmed to DQ7. The system
must provide the program address to read valid status
information on DQ7. If a program address falls within a
protected sector, Data# Polling on DQ7 is active for approximately 2 µs, then the device returns to reading
array data.
DQ7 = Data?
No
No
Read DQ7–DQ0
Addr = VA
DQ7 = Data?
Yes
No
FAIL
PASS
Notes:
1. VA = Valid address for programming. During a sector
erase operation, a valid address is an address within any
sector selected for erasure. During chip erase, a valid
address is any non-protected sector address.
2. DQ7 should be rechecked even if DQ5 = “1” because
DQ7 may change simultaneously with DQ5.
When the system detects DQ7 has changed from the
complement to true data, it can read valid data at DQ7–
DQ0 on the following read cycles. This is because DQ7
may change asynchronously with DQ0–DQ6 while
Output Enable (OE#) is asserted low. Figure 15, Data#
Polling Timings (During Embedded Algorithms), in the
“AC Characteristics” section illustrates this.
Table 6 shows the outputs for Data# Polling on DQ7.
Figure 4 shows the Data# Polling algorithm.
16
DQ5 = 1?
Yes
During the Embedded Erase algorithm, Data# Polling
produces a “0” on DQ7. When the Embedded Erase algorithm is complete, or if the device enters the Erase
Suspend mode, Data# Polling produces a “1” on DQ7.
This is analogous to the complement/true datum output
described for the Embedded Program algorithm: the
erase function changes all the bits in a sector to “1”;
prior to this, the device outputs the “complement,” or
“0.” The system must provide an address within any of
the sectors selected for erasure to read valid status information on DQ7.
After an erase command sequence is written, if all sectors selected for erasing are protected, Data# Polling
on DQ7 is active for approximately 100 µs, then the device returns to reading array data. If not all selected
sectors are protected, the Embedded Erase algorithm
erases the unprotected sectors, and ignores the selected sectors that are protected.
Yes
Am29F400B
21505C-8
Figure 4.
Data# Polling Algorithm
PRELIMINARY
RY/BY#: Ready/Busy#
The RY/BY# is a dedicated, open-drain output pin that
indicates whether an Embedded Algorithm is in
progress or complete. The RY/BY# status is valid after
the rising edge of the final WE# pulse in the command
sequence. Since RY/BY# is an open-drain output, several RY/BY# pins can be tied together in parallel with a
pull-up resistor to VCC.
If the output is low (Busy), the device is actively erasing
or programming. (This includes programming in the
Erase Suspend mode.) If the output is high (Ready),
the device is ready to read array data (including during
the Erase Suspend mode), or is in the standby mode.
Table 6 shows the outputs for RY/BY#. Figures 10, Figure 13 and Figure 14 shows RY/BY# for reset, program, and erase operations, respectively.
DQ6: Toggle Bit I
Toggle Bit I on DQ6 indicates whether an Embedded
Program or Erase algorithm is in progress or complete,
or whether the device has entered the Erase Suspend
mode. Toggle Bit I may be read at any address, and is
valid after the rising edge of the final WE# pulse in the
command sequence (prior to the program or erase operation), and during the sector erase time-out.
During an Embedded Program or Erase algorithm operation, successive read cycles to any address cause
DQ6 to toggle. The system may use either OE# or CE#
to control the read cycles. When the operation is complete, DQ6 stops toggling.
After an erase command sequence is written, if all sectors selected for erasing are protected, DQ6 toggles for
approximately 100 µs, then returns to reading array
data. If not all selected sectors are protected, the Embedded Erase algorithm erases the unprotected sectors, and ignores the selected sectors that are
protected.
The system can use DQ6 and DQ2 together to determine whether a sector is actively erasing or is erasesuspended. When the device is actively erasing (that is,
the Embedded Erase algorithm is in progress), DQ6
toggles. When the device enters the Erase Suspend
mode, DQ6 stops toggling. However, the system must
also use DQ2 to determine which sectors are erasing
or erase-suspended. Alternatively, the system can use
DQ7 (see the subsection on “DQ7: Data# Polling”).
If a program address falls within a protected sector,
DQ6 toggles for approximately 2 µs after the program
command sequence is written, then returns to reading
array data.
DQ6 also toggles during the erase-suspend-program
mode, and stops toggling once the Embedded Program algorithm is complete.
Table 6 shows the outputs for Toggle Bit I on DQ6. Figure 5 shows the toggle bit algorithm. Figure 16 in the
“AC Characteristics” section shows the toggle bit timing
diagrams. Figure 17 shows the differences between
DQ2 and DQ6 in graphical form. See also the subsection on “DQ2: Toggle Bit II”.
DQ2: Toggle Bit II
The “Toggle Bit II” on DQ2, when used with DQ6, indicates whether a particular sector is actively erasing
(that is, the Embedded Erase algorithm is in progress),
or whether that sector is erase-suspended. Toggle Bit
II is valid after the rising edge of the final WE# pulse in
the command sequence.
DQ2 toggles when the system reads at addresses
within those sectors that have been selected for erasure. (The system may use either OE# or CE# to control
the read cycles.) But DQ2 cannot distinguish whether
the sector is actively erasing or is erase-suspended.
DQ6, by comparison, indicates whether the device is
actively erasing, or is in Erase Suspend, but cannot distinguish which sectors are selected for erasure. Thus,
both status bits are required for sector and mode information. Refer to Table 6 to compare outputs for DQ2
and DQ6.
Figure 5 shows the toggle bit algorithm in flowchart
form, and the section “DQ2: Toggle Bit II” explains the
algorithm. See also the “DQ6: Toggle Bit I” subsection.
Figure 16 shows the toggle bit timing diagram. Figure
17 shows the differences between DQ2 and DQ6 in
graphical form.
Reading Toggle Bits DQ6/DQ2
Refer to Figure 5 for the following discussion. Whenever the system initially begins reading toggle bit status, it must read DQ7–DQ0 at least twice in a row to
determine whether a toggle bit is toggling. Typically, the
system would note and store the value of the toggle bit
after the first read. After the second read, the system
would compare the new value of the toggle bit with the
first. If the toggle bit is not toggling, the device has completed the program or erase operation. The system can
read array data on DQ7–DQ0 on the following read cycle.
However, if after the initial two read cycles, the system
determines that the toggle bit is still toggling, the system also should note whether the value of DQ5 is high
(see the section on DQ5). If it is, the system should
then determine again whether the toggle bit is toggling,
since the toggle bit may have stopped toggling just as
DQ5 went high. If the toggle bit is no longer toggling,
the device has successfully completed the program or
erase operation. If it is still toggling, the device did not
complete the operation successfully, and the system
must write the reset command to return to reading
array data.
Am29F400B
17
PRELIMINARY
The remaining scenario is that the system initially determines that the toggle bit is toggling and DQ5 has not
gone high. The system may continue to monitor the
toggle bit and DQ5 through successive read cycles, determining the status as described in the previous paragraph. Alternatively, it may choose to perform other
system tasks. In this case, the system must start at the
beginning of the algorithm when it returns to determine
the status of the operation (top of Figure 5).
DQ5: Exceeded Timing Limits
DQ5 indicates whether the program or erase time has
exceeded a specified internal pulse count limit. Under
these conditions DQ5 produces a “1.” This is a failure
condition that indicates the program or erase cycle was
not successfully completed.
START
The DQ5 failure condition may appear if the system
tries to program a “1” to a location that is previously programmed to “0.” Only an erase operation can change
a “0” back to a “1.” Under this condition, the device
halts the operation, and when the operation has exceeded the timing limits, DQ5 produces a “1.”
Read DQ7–DQ0
Under both these conditions, the system must issue the
reset command to return the device to reading array
data.
DQ3: Sector Erase Timer
Read DQ7–DQ0
(Note 1)
Toggle Bit
= Toggle?
No
After writing a sector erase command sequence, the
system may read DQ3 to determine whether or not an
erase operation has begun. (The sector erase timer
does not apply to the chip erase command.) If additional sectors are selected for erasure, the entire timeout also applies after each additional sector erase
command. When the time-out is complete, DQ3
switches from “0” to “1.” If the time between additional
sector erase commands from the system can be assumed to be less than 50 µs, the system need not
monitor DQ3. See also the “Sector Erase Command
Sequence” section.
Yes
No
DQ5 = 1?
After the sector erase command sequence is written,
the system should read the status on DQ7 (Data# Polling) or DQ6 (Toggle Bit I) to ensure the device has accepted the command sequence, and then read DQ3. If
DQ3 is “1”, the internally controlled erase cycle has begun; all further commands (other than Erase Suspend)
are ignored until the erase operation is complete. If
DQ3 is “0”, the device will accept additional sector
erase commands. To ensure the command has been
accepted, the system software should check the status
of DQ3 prior to and following each subsequent sector
erase command. If DQ3 is high on the second status
check, the last command might not have been accepted. Table 6 shows the outputs for DQ3.
Yes
Read DQ7–DQ0
Twice
Toggle Bit
= Toggle?
(Notes
1, 2)
No
Yes
Program/Erase
Operation Not
Complete, Write
Reset Command
Program/Erase
Operation Complete
Notes:
1. Read toggle bit twice to determine whether or not it is
toggling. See text.
2. Recheck toggle bit because it may stop toggling as DQ5
changes to “1”. See text.
21505C-9
Figure 5.
18
Toggle Bit Algorithm
Am29F400B
PRELIMINARY
Table 6.
DQ7
(Note 2)
DQ6
DQ5
(Note 1)
DQ3
DQ2
(Note 2)
RY/BY#
DQ7#
Toggle
0
N/A
No toggle
0
Embedded Erase Algorithm
0
Toggle
0
1
Toggle
0
Reading within Erase
Suspended Sector
1
No toggle
0
N/A
Toggle
1
Reading within Non-Erase
Suspended Sector
Data
Data
Data
Data
Data
1
Erase-Suspend-Program
DQ7#
Toggle
0
N/A
N/A
0
Operation
Standard
Mode
Erase
Suspend
Mode
Write Operation Status
Embedded Program Algorithm
Notes:
1. DQ5 switches to ‘1’ when an Embedded Program or Embedded Erase operation has exceeded the maximum timing limits.
See “DQ5: Exceeded Timing Limits” for more information.
2. DQ7 and DQ2 require a valid address when reading status information. Refer to the appropriate subsection for further details.
Am29F400B
19
PRELIMINARY
ABSOLUTE MAXIMUM RATINGS
Storage Temperature
Plastic Packages . . . . . . . . . . . . . . . –65°C to +150°C
Ambient Temperature
with Power Applied. . . . . . . . . . . . . . –55°C to +125°C
Voltage with Respect to Ground
VCC (Note 1) . . . . . . . . . . . . . . . .–2.0 V to +7.0 V
A9, OE#, and
RESET# (Note 2). . . . . . . . . . . . –2.0 V to +12.5 V
20 ns
20 ns
+0.8 V
–0.5 V
–2.0 V
20 ns
All other pins (Note 1) . . . . . . . . . –0.5 V to +7.0 V
Output Short Circuit Current (Note 3) . . . . . . 200 mA
21505C-10
Notes:
1. Minimum DC voltage on input or I/O pins is –0.5 V. During
voltage transitions, input or I/O pins may undershoot VSS
to –2.0 V for periods of up to 20 ns. See Figure 6.
Maximum DC voltage on input or I/O pins is VCC +0.5 V.
During voltage transitions, input or I/O pins may overshoot
to VCC +2.0 V for periods up to 20 ns. See Figure 7.
2. Minimum DC input voltage on pins A9, OE#, and RESET#
is –0.5 V. During voltage transitions, A9, OE#, and
RESET# may undershoot VSS to –2.0 V for periods of up
to 20 ns. See Figure 6. Maximum DC input voltage on pin
A9 is +12.5 V which may overshoot to +13.5 V for periods
up to 20 ns.
3. No more than one output may be shorted to ground at a
time. Duration of the short circuit should not be greater
than one second.
Figure 6.
20 ns
VCC
+2.0 V
VCC
+0.5 V
2.0 V
Stresses above those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. This is a
stress rating only; functional operation of the device at these
or any other conditions above those indicated in the operational sections of this data sheet is not implied. Exposure of
the device to absolute maximum rating conditions for extended periods may affect device reliability.
OPERATING RANGES
Commercial (C) Devices
Ambient Temperature (TA) . . . . . . . . . . . 0°C to +70°C
Industrial (I) Devices
Ambient Temperature (TA) . . . . . . . . . –40°C to +85°C
Extended (E) Devices
Ambient Temperature (TA) . . . . . . . . –55°C to +125°C
VCC Supply Voltages
VCC for ± 5% devices . . . . . . . . . . .+4.75 V to +5.25 V
VCC for ± 10% devices . . . . . . . . . . . .+4.5 V to +5.5 V
Operating ranges define those limits between which the functionality of the device is guaranteed.
20
Maximum Negative Overshoot
Waveform
Am29F400B
20 ns
20 ns
21505C-11
Figure 7.
Maximum Positive Overshoot
Waveform
PRELIMINARY
DC CHARACTERISTICS
TTL/NMOS Compatible
Parameter
Description
Test Conditions
ILI
Input Load Current
VIN = VSS to VCC, VCC = VCC max
ILIT
A9, OE#, RESET# Input Load
Current
VCC = VCC max;
A9, OE#, RESET# = 12.5 V
ILO
Output Leakage Current
VOUT = VSS to VCC, VCC = VCC max
ICC1
VCC Active Read Current
(Note 1)
Min
Typ
Max
Unit
±1.0
µA
50
µA
±1.0
µA
CE# = VIL, OE# = VIH, VCC = VCC max,
f = 5 MHz, Byte Mode
19
40
mA
CE# = VIL, OE# = VIH, VCC = VCC max,
f = 5 MHz, Word Mode
19
50
mA
ICC2
VCC Active Write Current
(Notes 2, 3)
CE# = VIL, OE# = VIH, VCC = VCC max
36
60
mA
ICC3
VCC Standby Current
CE#, RESET#, and OE# = VIH,
VCC = VCC max
0.4
1
mA
VIL
Input Low Voltage
–0.5
0.8
V
VIH
Input High Voltage
2.0
VCC
+0.5
V
VID
Voltage for Autoselect and
Temporary Sector Unprotect
VCC = 5.0 V
11.5
12.5
V
VOL
Output Low Voltage
IOL = 5.8 mA, VCC = VCC min
0.45
V
VOH
Output High Voltage
IOH = –2.5 mA, VCC = VCC min
VLKO
Low VCC Lock-Out Voltage
2.4
3.2
V
4.2
V
Notes:
1. The ICC current listed is typically less than 2 mA/MHz, with OE# at VIH.
2. ICC active while Embedded Erase or Embedded Program is in progress.
3. Not 100% tested.
Am29F400B
21
PRELIMINARY
DC CHARACTERISTICS
CMOS Compatible
Parameter
Description
Test Conditions
ILI
Input Load Current
VIN = VSS to VCC,
VCC = VCC max
ILIT
A9, OE#, RESET#
Input Load Current
VCC = VCC max;
A9, OE#, RESET# = 12.5 V
ILO
Output Leakage Current
VOUT = VSS to VCC,
VCC = VCC max
ICC1
VCC Active Read Current
(Note 1)
Typ
Max
Unit
±1.0
µA
50
µA
±1.0
µA
CE# = VIL, OE# = VIH,
VCC = VCC max, f = 5 MHz, Byte Mode
20
40
CE# = VIL, OE# = VIH,
VCC = VCC max, f = 5 MHz, Word Mode
28
50
mA
ICC2
VCC Active Write Current
(Notes 2, 3)
CE# = VIL, OE# = VIH,
VCC = VCC max
30
50
mA
ICC3
VCC Standby Current (Note 4)
OE# = VIH, CE# and RESET# = VCC±0.5 V,
VCC = VCC max
0.3
5
µA
VIL
Input Low Voltage
–0.5
0.8
V
VIH
Input High Voltage
0.7 x
VCC
VCC+
0.3
V
VID
Voltage for Autoselect and
Temporary Sector Unprotect
VCC = 5.0 V
11.5
12.5
V
VOL
Output Low Voltage
IOL = 5.8 mA, VCC = VCC min
0.45
V
VOH1
IOH = –2.5 mA, VCC = VCC min
0.85
VCC
IOH = –100 µA, VCC = VCC min
VCC–
0.4
Output High Voltage
VOH2
VLKO
Low VCC Lock-Out Voltage
3.2
Notes:
1. The ICC current listed is typically less than 2 mA/MHz, with OE# at VIH.
2. ICC active while Embedded Erase or Embedded Program is in progress.
3. Not 100% tested.
4. ICC3 = 20 µA max at extended temperature (>+85° C).
22
Min
Am29F400B
V
4.2
V
PRELIMINARY
TEST CONDITIONS
Table 7.
Test Specifications
5.0 V
Test Condition
2.7 kΩ
Device
Under
Test
CL
All
others
-55
Output Load
Unit
1 TTL gate
Output Load Capacitance, CL
(including jig capacitance)
30
100
pF
Input Rise and Fall Times
5
20
ns
0.0–3.0
0.45–2.4
V
Input timing measurement
reference levels
1.5
0.8, 2.0
V
Output timing measurement
reference levels
1.5
0.8, 2.0
V
6.2 kΩ
Input Pulse Levels
Note:
Diodes are IN3064 or equivalent.
21505C-12
Figure 8.
Test Setup
KEY TO SWITCHING WAVEFORMS
WAVEFORM
INPUTS
OUTPUTS
Steady
Changing from H to L
Changing from L to H
Don’t Care, Any Change Permitted
Changing, State Unknown
Does Not Apply
Center Line is High Impedance State (High Z)
KS000010-PAL
Am29F400B
23
PRELIMINARY
AC CHARACTERISTICS
Read Operations
Parameter
Speed Option
JEDEC
Std
Description
tAVAV
tRC
Read Cycle Time (Note 1)
tAVQV
tACC
Address to Output Delay
tELQV
tCE
Chip Enable to Output Delay
tGLQV
tOE
tEHQZ
tGHQZ
tAXQX
Test Setup
-55
-60
-70
-90
-120
-150
Unit
Min
55
60
70
90
120
150
ns
CE# = VIL
OE# = VIL
Max
55
60
70
90
120
150
ns
OE# = VIL
Max
55
60
70
90
120
150
ns
Output Enable to Output Delay
Max
30
30
30
35
50
55
ns
tDF
Chip Enable to Output High Z
(Note 1)
Max
15
20
20
20
30
35
ns
tDF
Output Enable to Output High Z
(Note 1)
Max
15
20
20
20
30
35
ns
tOEH
Output Enable Read
Hold Time
Toggle and
(Note 1)
Data# Polling
tOH
Output Hold Time From
Addresses, CE# or OE#,
Whichever Occurs First (Note 1)
Min
0
ns
Min
10
ns
Min
0
ns
Notes:
1. Not 100% tested.
2. See Figure 8 and Table 7 for test specifications.
tRC
Addresses Stable
Addresses
tACC
CE#
tDF
tOE
OE#
tOEH
WE#
tCE
tOH
HIGH Z
HIGH Z
Output Valid
Outputs
RESET#
RY/BY#
0V
21505C-13
Figure 9.
24
Read Operations Timings
Am29F400B
PRELIMINARY
AC CHARACTERISTICS
Hardware Reset (RESET#)
Parameter
JEDEC
Std
Description
Test Setup
All Speed Options
Unit
tREADY
RESET# Pin Low (During Embedded
Algorithms) to Read or Write (See Note)
Max
20
µs
tREADY
RESET# Pin Low (NOT During Embedded
Algorithms) to Read or Write (See Note)
Max
500
ns
tRP
RESET# Pulse Width
Min
500
ns
tRH
RESET# High Time Before Read (See Note)
Min
50
ns
tRB
RY/BY# Recovery Time
Min
0
ns
Note:
Not 100% tested.
RY/BY#
CE#, OE#
tRH
RESET#
tRP
tReady
Reset Timings NOT during Embedded Algorithms
Reset Timings during Embedded Algorithms
tReady
RY/BY#
tRB
CE#, OE#
RESET#
tRP
21505C-14
Figure 10.
RESET# Timings
Am29F400B
25
PRELIMINARY
AC CHARACTERISTICS
Word/Byte Configuration (BYTE#)
Parameter
JEDEC
Std.
Description
-55
-60
-70
-90
-120
-150
Unit
tELFL/tELFH
CE# to BYTE# Switching Low or High
Max
tFLQZ
BYTE# Switching Low to Output HIGH Z
Max
15
20
20
20
30
35
ns
tFHQV
BYTE# Switching High to Output Active
Min
55
60
70
90
120
150
ns
5
ns
CE#
OE#
BYTE#
BYTE#
Switching
from word
to byte
mode
tELFL
Data Output
(DQ0–DQ7)
Data Output
(DQ0–DQ14)
DQ0–DQ14
Address
Input
DQ15
Output
DQ15/A-1
tFLQZ
tELFH
BYTE#
BYTE#
Switching
from byte
to word
mode
Data Output
(DQ0–DQ7)
DQ0–DQ14
Address
Input
DQ15/A-1
Data Output
(DQ0–DQ14)
DQ15
Output
tFHQV
21505C-15
Figure 11.
BYTE# Timings for Read Operations
CE#
The falling edge of the last WE# signal
WE#
BYTE#
tSET
(tAS)
tHOLD (tAH)
Note:
Refer to the Erase/Program Operations table for tAS and tAH specifications.
21505C-16
Figure 12.
26
BYTE# Timings for Write Operations
Am29F400B
PRELIMINARY
AC CHARACTERISTICS
Erase/Program Operations
Parameter
JEDEC
Std.
Description
-55
-60
-70
-90
-120
-150
Unit
tAVAV
tWC
Write Cycle Time (Note 1)
Min
55
60
70
90
120
150
ns
tAVWL
tAS
Address Setup Time
Min
tWLAX
tAH
Address Hold Time
Min
45
45
45
45
50
50
ns
tDVWH
tDS
Data Setup Time
Min
25
30
30
45
50
50
ns
tWHDX
tDH
Data Hold Time
Min
0
ns
tOES
Output Enable Setup Time
Min
0
ns
Read Recovery Time Before Write
(OE# High to WE# Low)
Min
0
ns
0
ns
tGHWL
tGHWL
tELWL
tCS
CE# Setup Time
Min
0
ns
tWHEH
tCH
CE# Hold Time
Min
0
ns
tWLWH
tWP
Write Pulse Width
Min
tWHWL
tWPH
Write Pulse Width High
Min
20
Typ
7
tWHWH1
Programming Operation
(Note 2)
Byte
tWHWH1
Word
Typ
12
tWHWH2
tWHWH2 Sector Erase Operation (Note 2)
Typ
1
sec
30
35
35
45
50
50
ns
ns
µs
tVCS
VCC Setup Time (Note 1)
Min
50
µs
tRB
Recovery Time from RY/BY#
Min
0
ns
Program/Erase Valid to RY/BY#
Delay
Min
tBUSY
30
30
30
35
50
55
ns
Notes:
1. Not 100% tested.
2. See the “Erase and Programming Performance” section for more information.
Am29F400B
27
PRELIMINARY
AC CHARACTERISTICS
Program Command Sequence (last two cycles)
tAS
tWC
Addresses
555h
Read Status Data (last two cycles)
PA
PA
PA
tAH
CE#
tCH
tGHWL
OE#
tWHWH1
tWP
WE#
tWPH
tCS
tDS
tDH
A0h
Data
PD
Status
tBUSY
DOUT
tRB
RY/BY#
tVCS
VCC
Notes:
1. PA = program address, PD = program data, DOUT is the true data at the program address.
2. Illustration shows device in word mode.
21505C-17
Figure 13.
28
Program Operation Timings
Am29F400B
PRELIMINARY
AC CHARACTERISTICS
Erase Command Sequence (last two cycles)
tAS
tWC
2AAh
Addresses
Read Status Data
VA
SA
VA
555h for chip erase
tAH
CE#
tGHWL
tCH
OE#
tWP
WE#
tWPH
tCS
tWHWH2
tDS
tDH
Data
55h
In
Progress
30h
Complete
10 for Chip Erase
tBUSY
tRB
RY/BY#
tVCS
VCC
Notes:
1. SA = sector address (for Sector Erase), VA = Valid Address for reading status data (see “Write Operation Status”).
2. Illustration shows device in word mode.
21505C-18
Figure 14.
Chip/Sector Erase Operation Timings
Am29F400B
29
PRELIMINARY
AC CHARACTERISTICS
tRC
Addresses
VA
VA
VA
tACC
tCE
CE#
tCH
tOE
OE#
tOEH
tDF
WE#
tOH
High Z
DQ7
Complement
Complement
DQ0–DQ6
Status Data
Status Data
Valid Data
True
High Z
Valid Data
True
tBUSY
RY/BY#
Note:
VA = Valid address. Illustration shows first status cycle after command sequence, last status read cycle, and array data read cycle.
21505C-19
Figure 15.
Data# Polling Timings (During Embedded Algorithms)
tRC
Addresses
VA
VA
VA
VA
tACC
tCE
CE#
tCH
tOE
OE#
tOEH
tDF
WE#
tOH
High Z
DQ6/DQ2
tBUSY
Valid Status
Valid Status
(first read)
(second read)
Valid Status
Valid Data
(stops toggling)
RY/BY#
Note:
VA = Valid address; not required for DQ6. Illustration shows first two status cycle after command sequence, last status read cycle,
and array data read cycle.
21505C-20
Figure 16.
30
Toggle Bit Timings (During Embedded Algorithms)
Am29F400B
PRELIMINARY
AC CHARACTERISTICS
Enter
Embedded
Erasing
Erase
Suspend
Erase
WE#
Enter Erase
Suspend Program
Erase
Resume
Erase
Suspend
Program
Erase Suspend
Read
Erase
Complete
Erase
Erase Suspend
Read
DQ6
DQ2
Note:
The system may use either CE# or OE# to toggle DQ2 and DQ6. DQ2 toggles only when read at an address within an
erase-suspended sector.
21505C-21
Figure 17.
DQ2 vs. DQ6
Temporary Sector Unprotect
Parameter
JEDEC
Std.
Description
tVIDR
VID Rise and Fall Time (See Note)
tRSP
RESET# Setup Time for Temporary Sector
Unprotect
All Speed Options
Unit
Min
500
ns
Min
4
µs
Note: Not 100% tested.
12 V
RESET#
0 or 5 V
0 or 5 V
tVIDR
tVIDR
Program or Erase Command Sequence
CE#
WE#
tRSP
RY/BY#
21505C-22
Figure 18.
Temporary Sector Unprotect Timing Diagram
Am29F400B
31
PRELIMINARY
AC CHARACTERISTICS
Alternate CE# Controlled Erase/Program Operations
Parameter
JEDEC
Std.
Description
-55
-60
-70
-90
-120
-150
Unit
tAVAV
tWC
Write Cycle Time (Note 1)
Min
55
60
70
90
120
150
ns
tAVEL
tAS
Address Setup Time
Min
tELAX
tAH
Address Hold Time
Min
45
45
45
45
50
50
ns
tDVEH
tDS
Data Setup Time
Min
25
30
30
45
50
50
ns
tEHDX
tDH
Data Hold Time
Min
0
ns
tOES
Output Enable Setup Time
Min
0
ns
tGHEL
tGHEL
Read Recovery Time Before Write
(OE# High to WE# Low)
Min
0
ns
tWLEL
tWS
WE# Setup Time
Min
0
ns
tEHWH
tWH
WE# Hold Time
Min
0
ns
tELEH
tCP
CE# Pulse Width
Min
tEHEL
tCPH
CE# Pulse Width High
Min
20
Typ
7
tWHWH1
Programming Operation
(Note 2)
Byte
tWHWH1
Word
Typ
12
tWHWH2
tWHWH2
Sector Erase Operation (Note 2)
Typ
1
0
30
35
45
50
50
ns
ns
µs
Notes:
1. Not 100% tested.
2. See the “Erase and Programming Performance” section for more information.
32
35
ns
Am29F400B
sec
PRELIMINARY
AC CHARACTERISTICS
555 for program
2AA for erase
PA for program
SA for sector erase
555 for chip erase
Data# Polling
Addresses
PA
tWC
tAS
tAH
tWH
WE#
tGHEL
OE#
tCP
CE#
tWS
tWHWH1 or 2
tCPH
tBUSY
tDS
tDH
DQ7#
Data
tRH
A0 for program
55 for erase
DOUT
PD for program
30 for sector erase
10 for chip erase
RESET#
RY/BY#
Notes:
1. PA = Program Address, PD = Program Data, SA = Sector Address, DQ7# = Complement of Data Input, DOUT = Array Data.
2. Figure indicates the last two bus cycles of the command sequence, with the device in word mode.
21505C-23
Figure 19.
Alternate CE# Controlled Write Operation Timings
Am29F400B
33
PRELIMINARY
ERASE AND PROGRAMMING PERFORMANCE
Parameter
Typ (Note 1)
Max (Note 2)
Unit
Sector Erase Time
1.0
8
s
Chip Erase Time
11
Byte Programming Time
7
300
µs
Word Programming Time
12
500
µs
s
Chip Programming Time
Byte Mode
3.6
10.8
s
(Note 3)
Word Mode
3.1
9.3
s
Comments
Excludes 00h programming
prior to erasure
Excludes system level
overhead (Note 5)
Notes:
1. Typical program and erase times assume the following conditions: 25°C, 5.0 V VCC, 1,000,000 cycles. Additionally,
programming typicals assume checkerboard pattern.
2. Under worst case conditions of 90°C, VCC = 4.5 V (4.75 V for -60), 1,000,000 cycles.
3. The typical chip programming time is considerably less than the maximum chip programming time listed, since most bytes
program faster than the maximum program times listed.
4. In the pre-programming step of the Embedded Erase algorithm, all bytes are programmed to 00h before erasure.
5. System-level overhead is the time required to execute the four-bus-cycle sequence for the program command. See Table 5
for further information on command definitions.
6. The device has a guaranteed minimum erase and program cycle endurance of 1,000,000 cycles.
LATCHUP CHARACTERISTICS
Description
Min
Max
Input voltage with respect to VSS on all pins except I/O pins
(including A9, OE#, and RESET#)
–1.0 V
12.5 V
Input voltage with respect to VSS on all I/O pins
–1.0 V
VCC + 1.0 V
–100 mA
+100 mA
VCC Current
Includes all pins except VCC. Test conditions: VCC = 5.0 V, one pin at a time.
TSOP AND SO PIN CAPACITANCE
Parameter
Symbol
Parameter Description
Test Setup
Typ
Max
Unit
CIN
Input Capacitance
VIN = 0
6
7.5
pF
COUT
Output Capacitance
VOUT = 0
8.5
12
pF
CIN2
Control Pin Capacitance
VIN = 0
7.5
9
pF
Notes:
1. Sampled, not 100% tested.
2. Test conditions TA = 25°C, f = 1.0 MHz.
DATA RETENTION
Parameter
Test Conditions
Min
Unit
150°C
10
Years
125°C
20
Years
Minimum Pattern Data Retention Time
34
Am29F400B
PRELIMINARY
PHYSICAL DIMENSIONS
TS 048
48-Pin Standard Thin Small Outline Package (measured in millimeters)
0.95
1.05
Pin 1 I.D.
1
48
11.90
12.10
0.50 BSC
24
25
0.05
0.15
18.30
18.50
19.80
20.20
1.20
MAX
0°
5°
0.25MM (0.0098") BSC
16-038-TS48-2
TS 048
DT95
8-8-96 lv
0.08
0.20
0.10
0.21
0.50
0.70
TSR048
48-Pin Reverse Thin Small Outline Package (measured in millimeters)
0.95
1.05
Pin 1 I.D.
1
48
11.90
12.10
0.50 BSC
24
25
0.05
0.15
18.30
18.50
19.80
20.20
SEATING PLANE
0.08
0.20
0.10
0.21
1.20
MAX
0.25MM (0.0098") BSC
0°
5°
16-038-TS48
TSR048
DT95
8-8-96 lv
0.50
0.70
Am29F400B
35
PRELIMINARY
PHYSICAL DIMENSIONS
SO 044
44-Pin Small Outline Package (measured in millimeters)
44
23
13.10
13.50
1
15.70
16.30
22
1.27 NOM.
TOP VIEW
28.00
28.40
2.17
2.45
0.10
0.21
2.80
MAX.
0.35
0.50
0.10
0.35
SEATING
PLANE
SIDE VIEW
36
0°
8°
0.60
1.00
END VIEW
16-038-SO44-2
SO 044
DF83
8-8-96 lv
Am29F400B
PRELIMINARY
REVISION SUMMARY
Revision B
Revision C
Global
Global
Added -55 and -60 speed options, deleted -65 speed
option. Changed data sheet designation from Advance
Information to Preliminary.
Formatted for consistency with other 5.0 volt-only data
sheets.
Connection Diagrams
Changed tDF and TFLQZ to 15 ns for -55 speed option.
AC Characteristics
Corrected pinouts on all packages: deleted A18.
Revision C+1
Table 1, Device Bus Operations
Revised to indicate inputs for both CE# and RESET#
are required for standby mode.
Sector Protection/Unprotection
Corrected text to indicate that these functions can only
be implemented using programming equipment.
Table 2, Top Boot Block Sector Address Table
Corrected the sector size for SA10 to 16 Kbytes/8
Kwords.
DC Characteristics—TTL/NMOS Compatible
Deleted Note 4.
Program Command Sequence
Revision C+2
Changed to indicate Data# Polling is active for 2 µs
after a program command sequence if the sector specified is protected.
Distinctive Characteristics
Sector Erase Command Sequence and DQ3: Sector
Erase Timer
AC Characteristics
Corrected sector erase timeout to 50 µs.
Erase Suspend Command
Changed to indicate that the device suspends the
erase operation a maximum of 20 µs after the rising
edge of WE#.
DC Characteristics
Changed minimum 100K write/erase cycles guaranteed to 1,000,000.
Word/Byte Configuration: Changed tFHQV specification
for 55 ns device.
Erase/Program Operations: Changed t WHWH1 word
mode specification to 12 µs. Corrected the notes reference for tWHWH1 and tWHWH2. These parameters are
100% tested. Corrected the note reference for tVCS.
This parameter is not 100% tested.
Changed to indicate VID min and max values are 11.5
to 12.5 V, with a VCC test condition of 5.0 V. Revised ILIT
to 50 µA. Added ICC4 specification. Added typical
values to TTL/NMOS table. Revised CMOS typical
standby current (ICC3).
Changed tDS and tCP specifications for 55 ns device.
Figure 14: Chip/Sector Erase Operation Timings;
Figure 19: Alternate CE# Controlled Write
Operation TImings
Changed tDS and tCP specifications for 55 ns device.
Corrected hexadecimal values in address and data
waveforms.
Added note reference for tVIDR. This parameter is not
100% tested.
AC Characteristics, Erase/Program Operations
Erase and Programming Performance
Corrected tAH specification for -90 speed option to 45
ns.
Changed minimum 100K program and erase cycles
guaranteed to 1,000,000.
Alternate CE# Controlled Erase/Program Operations:
Changed tWHWH1 word mode specification to 12 µs.
Corrected the notes reference for tWHWH1 and tWHWH2.
These parameters are 100% tested.
Temporary Sector Unprotect Table
Erase and Programming Performance
Corrected word and chip programming times.
Trademarks
Copyright © 1998 Advanced Micro Devices, Inc. All rights reserved.
AMD, the AMD logo, and combinations thereof are registered trademarks of Advanced Micro Devices, Inc.
ExpressFlash is a trademark of Advanced Micro Devices, Inc.
Product names used in this publication are for identification purposes only and may be trademarks of their respective companies.
Am29F400B
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