The Am28F512A is a 512 Kbit Flash memory organized as 64 Kbytes of 8 bits each. AMD’s Flash memories offer the most cost-eff ectiv e and reliab le r ead/write
non- volatile rand om access memory . The Am28F512A
is packaged in 32-pin PDIP, PLCC, and TSOP versions .
It is designed to be reprogrammed and erased in-system or in standard EPROM programmers. The
Am28F512A is erased when shipped from the factory.
The standard Am28F512A offers access times as fast
as 70 ns, allowing operation of high-spee d microprocessors without wait states. To eliminate bus contention, the Am28F512A has separate chip enable (CE#)
and output enable (OE#) controls.
AMD’s Flash memories augment EPROM functionality
with in-circuit electrical erasure and programming. The
Am28F512A uses a command register to manage this
functionality, while maintaining a JEDEC Flash standard 32-pin pinout. The command register allows for
100% TTL level control inputs and fixed power supply
levels during erase and programming.
AMD’s Flash technology reliably stores me mory contents even after 100,000 erase and program cycles.
The AMD cell is designed to optimize the erase and
programming mechanisms. In addition, the combination of advanced tunnel o xide processing and l ow internal electric fields for erase and programming
operations produces reliable cycling. The Am28F512A
uses a 12.0V ± 5% V
the erase
The highest degree of latch-up protection is achieved
with AMD’s proprietary non-epi process. Latch-up protection is provided for stresses up to 100 milliamps on
address and data pins from –1 V to V
and programming functions.
high voltage i nput to perfor m
PP
+1 V.
CC
Embedded Program
The Am28F512A is byte programmable using the Embedded Programming algorithm. The Embedded Programming algor ithm does not requir e the system to
time-out or verify the data programmed. The typical
room temperature programming time of the
Am28F512A is one second.
Embedded Erase
The entire chip is bulk erased using the Embedded
Erase algorithm. The Embedded
matically programs the entire array prior to electrical
erase. The timing and verification of electrical erase are
Erase algorithm auto-
Publication# 18880 Rev: C Amendment/+2
Issue Date: April 1998
controlled internal to the device. Typical erasure at room
temperature is accomplished in two seconds, including
programming.
Comparing Embedded Algorithms with Flasherase and Flashrite Algorithms
AMD’s Am28F512A is entirely pin and software compatible with AMD Am28F020A, Am28F010A, and
Am28F256A Flash memories.
Embedded
Programming
Algorithm vs.
Flashrite
Programming
Algorithm
Embedded Erase
Algorithm vs.
Flasherase Erase
Algorithm
Am28F512A with
Embedded Algorithms
AMD’s Embedded Programming algorithm
requires the user to only write a program
set-up command and a program command
(program data and address). The device
automatically times the programming
pulse width, verifies the programming, and
counts the number of sequences. A status
bit, Data
the programming operation status.
AMD’s Embedded Erase algorithm
requires the user to only write an erase setup command and erase command. The
device automatically pre-programs and
verifies the entire array. The device then
automatically times the erase pulse width,
verifies the erase operation, and counts
the number of sequences. A status bit,
Data
erase operation status.
# Polling, provides the user with
# Polling, provides the user with the
Am28F512 using AMD Flashrite
and Flasherase Algorith ms
The Flashrite Programming algorithm requires the
user to write a program set-up command, a program
command, (program data and address), and a
program verify command, followed by a read and
compare operation. The user is required to time the
programming pulse width in order to issue the
program verify command. An integrated stop timer
prevents any possibility of overprogramming.
Upon completion of this sequence, the data is read
back from the device and compared by the user with
the data intended to be written; if there is not a
match, the sequence is repeated until there is a
match or the sequence has been repeated 25 times.
The Flasherase Erase algorithm requires the device
to be completely programmed prior to executing an
erase command.
To invoke the erase operation, the user writes an
erase set-up command, an erase command, and an
erase verify command. The user is required to time
the erase pulse width in order to issue the erase
verify command. An integrated stop timer prevents
any possibility of overerasure.
Upon completion of this sequence, the data is read
back from the device and compared by the user with
erased data. If there is not a match, the sequence is
repeated until there is a match or the sequence has
been repeated 1,000 times.
Commands are written to the command register using
standard microprocessor write timings. Register contents serve as inputs to an internal state-machine
which controls the erase and programming circuitry.
During write cycles, the command register internally
latches address and data needed for the programming and erase operations. For system design simplification, the Am28F512 A is designed to support either
WE# or CE controlled writes. Dur ing a system write
cycle, addresses are latched on the falling edge of
WE# or CE# whiche v er occurs last . Data i s latched on
the rising edge of WE# or CE# whichever occurs firs t.
To simplify the following discussion, the W E# pin is
used as the write cycle cont rol pin thr oug hout the r es t
of this text. All setup and hold times are with respect
to the WE# signa l.
AMD’s Flash technology combines years of EPROM
and EEPROM experience to produce the highest levels of quality, reliability, and cost effectiveness. The
Am28F512A electr ically erases all bits simultaneously using Fowler-Nordheim tunneling. The bytes
are programmed one byte at a time using the EPROM
programming mechanism of hot electron injection.
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.
6Am28F512A
Valid Combinations
PIN DESCRIPTION
A0–A15
ddress Inputs for memory locations. Internal latches
A
hold addresses during write cycles.
CE# (E#)
Chip Enable active low input activates the chip’s control logic and input buffers. Chip Enable high will deselect the device and operates the chip in stand-by mode.
DQ0–DQ7
Data Inputs during memory write cycles. Internal
latches hold data during write cycles. Data Outputs
during memory read cycles.
NC
No Connect-corresponding pin is not connected
internally to the die.
OE# (G#)
Output Enable active low input gates the outputs of the
device through the data buffers during memory read
cycles. Output Enable is high during command
sequencing and program/erase operations.
V
CC
Pow er supply f or de vice operat ion. (5.0 V ± 5% or 10%)
V
PP
Program voltage input. VPP must be at high voltage in
order to write to the command register. The command
register controls all functions required to alt er the memory array contents. Memory contents cannot be a ltered
when V
V
SS
Ground.
PP
≤ V
CC
+2 V.
WE# (W#)
Write Enable active low input controls the write function
of the command register to the memory array. The target address is latched on the falling edge of the Write
Enable pulse and the appropriate data is latched on the
rising edge of the pulse. Write Enable high inhibits
writing to the device.
Am28F512A7
BASIC PRINCIPLES
This section contains descriptions about the device
read, erase, and program operations, and write operation status of the Am29FxxxA, 12.0 volt f amily of Flash
devices. References to some tables or figures may be
given in generic form, such as “Command Definitions
table”, rather than “ Table 1”. Refer to the corresponding
data sheet for the actual table or figure.
The Am28FxxxA family uses 100% TTL-level control
inputs to manage the comman d register. Erase and
reprogramming operations use a fixed 12.0 V ± 5%
high voltage input.
Read Only Memory
Without high VPP voltage, the device functions as a
read only memory and operates like a standard
EPROM. The control inputs still manage traditional
read, standby, out put disable, and Auto select modes.
Command Register
The command register is enabled only when high voltage is applied to the V
gramming operations are only accessed via the
register. In addit i on, two-cycle commands are required
for erase and reprogramming operations. The traditional read, standby, output disable, and Auto select
modes are available via the register.
The device’s command register is written using standard
microprocessor write timings. The register controls an
intern al state machi ne that manag es all device operations. For system design simplification, the device is designed to support either WE# or CE # controlled writes.
During a system write cycle, addresses are latched on
the falling edge of WE# o r CE# whichever occurs last .
Data is latched on the rising edge of WE# or CE# whichever occur first. To simplify the following discussion, the
WE# pin is used as the write cycle control pin throughout
the rest of this text. All setup and hold times are with respect to the WE# signal.
pin. The erase and repro-
PP
OVERVIEW OF ERASE/PROGRAM
OPERATIONS
Embedded
AMD now makes erasure extremely simple and reliable. The Embedded Erase algorithm requires the user
to only write an erase setup command and erase command. The device will automatica lly pre-program and
verify the entire array. The device automatically times
the erase pulse width, provides the erase verify and
counts the number of sequences. A status bit, Data#
Polling, provides feedback to the user as to the status
of the erase operation.
Erase Algorithm
Embedded Programming Algorithm
AMD now makes programming extremely simple and
reliable. The Embedded Programming algorithm requires the user to only write a program setup command
and a program command. The device automatically
times the programming pulse width, provides the program verify and counts the number of sequences. A
status bit, Data# Polling, provides feedback to the user
as to the status of the programming operation.
DATA PROTECTION
The device is designed to offer protection against accidental erasur e or programming ca used by spurious
system level signals that ma y e xist during power t ransitions. The device po wers up in its read only state . Also,
with its control register architecture, alteration of the
memory contents only occurs after successful completion of specific command sequences.
The device also incor porates several features to prevent inadvertent wr ite cycles resulting from V
power-up and power-down trans itions or system noise.
CC
Low VCC Write Inhibit
To avoid initiation of a write cycle during VCC power-up
and power-down, the device locks out write cycles for
< V
V
CC
ages). When V
abled, all internal program/erase circuits are disabled,
and the device resets to the read mode. The dev ic e ignores all writes until V
that the control pins are in the correct logic state when
> V
V
CC
(see DC characteristics section for volt-
LKO
LKO
< V
CC
to prevent unintentional writes.
, the command register is dis-
LKO
> V
CC
. The user must ensure
LKO
Write Pulse “Glitch” Protection
Noise pulses of less than 10 ns (typical) on OE#, CE#
or WE# will not initiate a write cycle.
Logical Inhibit
Writing is inhibited by holding any one of OE# = VIL,
CE# =V
and WE# must be a logical zero while OE# is a logical
one.
or WE# = VIH. To initiate a write cycle CE#
IH
Power-Up Write Inhibit
Power-up of the device with WE# = CE# = VIL and
OE# = V
edge of WE#. The internal state machine is automatically reset to the read mode on power-up.
will not accept commands on the rising
IH
8Am28F512A
FUNCTIONAL DESCRIPTION
Description Of User Modes
Table 1. Am28F512A Device Bus Operations (Notes 7 and 8)
. 0 V < An < VCC + 2 V, (normal TTL or CMOS input levels, where n = 0 or 9).
PPH
or VIH levels. V
IL
= VPP < VCC + 2 V. See DC Characteristics for voltage levels
PPL
Notes:
1. V
may be grounded, connected with a resistor to ground, or < VCC + 2.0 V . V
PPL
the device. Refer to the DC characteristics. When V
PP
= V
, memory contents can be read but not written or erased.
PPL
is the programming voltage specified for
PPH
2. Manufacturer and device codes may also be accessed via a command register write sequence. Refer to Table 2.
3. 11.5 < V
4. Read operation with V
5. With V
6. Refer to Table 3 for valid D
7. All inputs are Don’t Care unless otherwise stated, where Don’t Care is either V
addresses except A
8. If V
< 13.0 V. Minimum VID rise time and fall time (between 0 and VID voltages) is 500 ns.
ID
= V
PP
at high voltage, the standby current is ICC + IPP (standby).
PP
and A0 must be held at VIL.
9
≤
1.0 Volt, the voltage difference between VPP and VCC should not exceed 10.0 volts. Also, the Am28F256 has a VPP
CC
may access array data or the Auto select codes.
PPH
during a write operation.
IN
or VIH levels. In the Auto select mode all
IL
rise time and fall time specification of 500 ns minimum.
OUT
CODE
(01h)
CODE
(AEh)
D
OUT
(Note 4)
D
IN
(Note 6)
Am28F512A9
READ-ONLY MODE
When VPP is less than V
is inactive. The device can either read array or autoselect data, or be standby mode.
+ 2 V , the command register
CC
Read
The device functions as a read only memory when V
< V
+ 2 V. The de vice has two control functi ons. Both
CC
must be satisfied in order to output data. CE# controls
power to the device. This pin should be used for specific device selection. OE# controls the device outputs
and should be used to gate data to the output pins if a
device is selected.
Address access time t
is equal to the delay from
ACC
stable addresses to valid output data. The chip enable
access time t
is the delay from st able addres ses and
CE
stable CE# to valid data at the output pins. The output
enable access time is the delay from the f alling edge of
OE# to valid data at the output pins (assuming the addresses have been stable at least t
ACC
- tOE).
PP
Standby Mode
The device has two standby modes. The CMOS
standby mode (CE# input held at V
sumes less than 100 µA of current. TTL standby mode
(CE# is held at V
) reduces the current requirements
IH
to less than 1 mA. When in the standby mode the outputs are in a high impedance state, independent of the
OE# input.
If the device is deselected during erasure, programming, or program/erase verification, the device will
draw activ e current until the operation is terminated.
± 0.5 V), con-
CC
Output Disable
Output from the device is disabled whe n OE# is at a
logic high level. When disabled, output pins are in a
high impedance state.
Auto Select
Flash memories can be programmed in-system or in a
standard PROM programmer. The device may be soldered to the circuit board upon receipt of shipment and
programmed in-system. Alternatively, the device may
initially be programmed in a PROM programmer prior
to soldering the device to the board.
The Auto select mode allows the reading out of a binary
code from the device that will identify its manufacturer and
type. This mode is intended for the purpos e of autom atically matching the device to be programmed with its corresponding p rogramming algorithm . This mode is
functional over the entire temperature range of the device.
Programming In A PROM Programmer
To activate this mode, the programming equipment
must force V
identifier bytes ma y then be sequenced from the device
outputs by toggling address A0 f rom V
address lines must be held at V
less than or equal to V
select mode. Byte 0 (A0 = V
turer code and byte 1 (A0 = V
code. For t he device t he two b ytes are given in the table
2 of the device data sheet. All identifiers for manufacturer and device codes will exhibit odd parity with the
MSB (DQ7) defined as the parity bit.
(11.5 V to 13.0 V) on address A9. Two
ID
to VIH. All other
IL
, and VPP must be
+ 2.0 V while using this Auto
CC
IL
) represents the manufac-
IL
) the device identifier
IH
Table 2. Am28F512A Auto Select Code
TypeA0
Manufacturer CodeV
Device CodeV
10Am28F512A
Code
(HEX)
IL
IH
01
AE
ERASE, PROGRAM, AND READ MODE
When VPP is equal to 12.0 V ± 5%, the command reg-
ister is active. All functions are available. That is, the
device can program, erase, read array or autoselect
data, or be standby mode.
Write Operations
High voltage must be applied to the VPP pin in order to
activate the command register. Data written to the register serves as input to the internal state machine. The
output of the state machine determines the operational
function of the device.
The command register does not occupy an addressable memory location. The register is a latch that stores
the command, along with the address and data information needed to execute the command. The register
is written by bringing WE# and CE# to V
is at V
. Addresses are latched on the falling edge of
IH
WE#, while data is latched on the rising edge of the
WE# pulse. Standard microprocessor write timings are
used.
The device requires the OE# pin to be V
erations. This condition eliminates the possi bility for
bus contention during programming operations. In
order to write, OE# must be V
must be V
. If any pin is not in the correct state a write
IL
, and CE# and WE#
IH
command will not be executed.
, while OE#
IL
for write op-
IH
Refer to AC Write Characteristics and the Erase/Programming Waveforms for specific timing parameters.
Command Definitions
The contents of the command register default to 00h
(Read Mode) in the abs ence of hi gh v oltage applie d to
the V
memory. High voltage on the V
pin. The device operates as a read only
PP
pin enables the
PP
command register. Device operations are selected by
writing specific data codes i nto the command regi ster.
Tabl e 3 in the de vice data sheet def ines these regis ter
commands.
Read Command
Memory contents can be accessed via the read command when V
00h into the command register. Standard microprocessor read cycles access data from the memory. The device will remain in the read mode until the command
register contents are altered.
The command register defaults to 00h (read mode)
upon V
PP
fault helps ensure that inadvertent alteration of the
memory contents does not occur during the V
transition. Refer to the AC Read Characteristics and
Waveforms for the specific timing parameters.
is high. To read from the device, write
PP
power-up. The 00h (Read Mode) register de-
power
PP
Table 3. Am28F512A Command Definitions
First Bus CycleSecond Bus Cycle
Operation
Command
Read Memory (Note 4)WriteX00h/FFhReadRARD
Read Auto selectWriteX80h or 90hRead00h/01h01h/AEh
Embedded Erase Set-up/
Embedded Erase
Embedded Program Set-up/
Embedded Program
Reset (Note 4)WriteX00h/FFhWriteX00h/FFh
Notes:
1. Bus operations are defined in Table 1.
2. RA = Address of the memory location to be read.
PA = Address of the memory location to be programmed.
Addresses are latched on the falling edge of the WE
X = Don’t care.
3. RD = Data read from location RA during read operation.
PD = Data to be programmed at location PA. Data latched on the rising edge of WE
4. Please reference Reset Command section.
(Note 1)
WriteX30hWriteX30h
WriteX10h or 50hWritePAPD
Address
(Note 2)
#
pulse.
Data
(Note 3)
Operation
(Note 1)
#
.
Address
(Note 2)
Data
(Note 3)
Am28F512A11
FLASH MEMORY PROGRAM/ERASE
OPERATIONS
Embedded Erase Algorithm
The automatic chip erase does not require the device
to be entirely pre-programmed prior to executing the
Embedded set-up erase comm and and Embedded
erase command. Upon ex ecuting the Embedded erase
command the device automatically will program and
verify the entire memor y for an all zero data patter n.
not
The system is
timing during these operations.
required to provide any controls or
has been achiev ed f or the memory arra y ( no eras e v erify command is required). The margin voltages are internally generated in the same manner as when the
standard erase verify command is used.
The Embedded Erase Set-Up command is a command
only operation that stages the device for automatic
electrical erasure of all bytes in the array. Embedded
Erase Setup is performed by writing 30h to the command register.
When the device is automatical ly verified to contain an
all zero pattern, a self-timed chip erase and verify begin. The erase and ve rify oper ation are c omplete when
the data on DQ7 is “1" (see Write Operation Status section) atwhich time the device returns to Read mode.
The system is not required to provide any control or
timing during these operations.
When using the Embedded Erase algorithm, the erase
automatically terminates when adequate erase margin
Apply V
Write Embedded Erase Setup Command
Write Embedded Erase Command
Data# Poll from Device
To commence automatic chip erase, the command 30h
must be written again to the command register . The automatic erase begins on the rising edge of the WE and
terminates when the data on DQ7 is “1" (see Write Operation Status section) at which time the device returns
to Read mode.
Figure 1 and Table 4 illustrate the Embedded Erase algorithm, a typical command string and bus operation.
START
PPH
Erasure Completed
Figure 1. Embedded Erase Algorithm
Table 4.Embedded Erase Algorithm
Bus OperationsCommandComments
StandbyWait for V
Write
ReadData
StandbyCompare Output to FFh
ReadAvailable for Read Operations
Note: See AC and DC Characteristics for values of V
switchable. When V
to Functional Description.
may be ground, no connect with a resistor tied to ground, or less than VCC + 2.0 V. Refer
PPL
PP
Ramp to V
PP
# Polling to Verify Erasure
power supply can be hard-wired to the device or
PP
(see Note)
PPH
12Am28F512A
18880C-6
Embedded Programming Algorithm
The Embedded Program Setup is a command only operation that stages the device for automatic programming. Embedde d Program Setup is performed by
writing 10h or 50h to the command register.
Once the Embedded Setup Progr am ope r ation is performed, the next WE# pulse causes a transition to an
active prog ramming operati on. Ad dresses are latched
on the falling edge of CE# or WE# pulse, whichever
happens later. Data is latched on the rising edge of
WE# or CE#, whiche ver happens first. The ris ing edge
of WE# also begins the programming operation. The
system is not required to provide further controls or
timings. The device will automatically provide an adequate internally generated program pulse and verify
margin. The automatic programming operation is
completed when the data on DQ7 is equiva lent to data
written to this bit (see Write Oper at io n Stat us s ecti on)
at which time the device returns to Read mode.
Figure 2 and Table 5 illustrate the Embedded Program
algorithm, a typical command string, and bus operation.
START
Increment Address
Apply V
Write Embedded Setup Program Command
Write Embedded
Data# Poll Device
No
Last Address
Programming Completed
PPH
Program Command (A/D)
Yes
Figure 2. Embedded Programming Algorithm
Table 5. Embedded Programming Algorithm
Bus OperationsCommandComments
18880C-7
StandbyWait for V
WriteEmbedded Program Setup CommandData = 10h or 50h
WriteEmbedded Program CommandValid Address/Data
ReadData
ReadAvailable for Read Operations
Note: See AC and DC Characteristics for values of V
switchable. When V
to Functional Description. Device is either powered-down, erase inhibit or program inhibit.
is switched, V
PP
may be ground, no connect with a resistor tied to ground, or less than VCC + 2.0 V. Refer
PPL
parameters. The V
PP
Ramp to V
PP
PPH
# Polling to Verify Completion
power supply can be hard-wired to the device or
PP
Am28F512A13
(see Note)
Write Operation Status
Data Polling—DQ7
The device features Data# Polling as a method to indicate to the host system that the Embedded algorithms
are either in progress or completed.
While the Embedded Programming algorithm is in operation, an attempt to read the device at a valid address
will produce the complement of expected Valid data on
DQ7. Upon completion of the Embedded Program algorithm an attempt to read the device at a valid address will
produce Valid data on DQ7. The Data# Polling feature is
valid after the rising edge of the se cond WE# pulse of
the two write pulse sequence.
START
While the Embedded Erase algorithm is in operation,
DQ7 will read “0"
until the erase operation is completed. Upon completion of the eras e operation, the
data on DQ7 will read “1.” The Data# Polling feature is
valid after the rising edge of the second WE# pulse of
the two Write pulse sequence.
The Data# Polling feature is only active during Embedded Programming or erase algorithms.
See Figures 3 and 4 for the Data# Polling timing specifications and diagrams. Data# Polling is the standard
method to check the write operation status, however,
an alternative method is available using Toggle Bit.
No
Read Byte
(DQ0–DQ7)
Addr = VA
DQ7 = Data
?
No
DQ5 = 1
?
Yes
Read Byte
(DQ0–DQ7)
Addr = VA
DQ7 = Data
?
No
VA = Byte address for programming
= XXXXh during chip erase
Yes
Yes
Fail
Note:
DQ7 is rechecked even if DQ5 = “1” because DQ7 may change simultaneously with DQ5 or after DQ5.
Pass
Figure 3. Data# Polling Algorithm
14Am28F512A
18880C-8
CE#
t
CH
t
t
OE
DF
OE#
t
OEH
WE#
DQ7
t
CE
t
WHWH 3 or 4
DQ7#
DQ0–DQ6 = InvalidDQ0–DQ6
*DQ7 = Valid Data (The device has completed the Embedded operation.)
Figure 4. AC Waveforms for Data# Polling during Embedded Algorithm Operations
*
DQ7 =
Valid Data
t
OH
DQ0–DQ7
Valid Data
High Z
18880C-9
Am28F512A15
Toggle Bit—DQ6
The device also f eatures a “Toggle Bit” as a method to
indicate to the host system that the Embedded algorithms are either in progres s or completed.
Successive attempts to read data from the device at a
valid address, while the Embedded Program algorithm
is in progress, or at any address while the Embedded
Erase algorithm is in progress, will result in D Q6 toggling between one and zero. Once the Embedded Program or Erase algor ithm is completed, D Q6 will stop
START
toggling to indicate the completion of either Embedded
operation. Only on the next read cycl e will valid data be
obtained. The toggle bit is valid after the rising edge of
the first WE# pulse of the two write pulse seq uence, unlike Data# Polling which is valid after the rising edge of
the second WE# pulse. This feature allows the user to
determine if the device is partially through the two write
pulse sequence.
See Figures 5 and 6 for the Toggle Bit timing specifications and diagrams.
Read Byte
(DQ0–DQ7)
Addr = VA
DQ6 = Toggle
No
Read Byte
(DQ0–DQ7)
Addr = VA
DQ6 = Toggle
VA = Byte address for programming
= XXXXh during chip erase
No
?
Yes
DQ5 = 1
?
Yes
No
?
Yes
Fail
Note:
DQ6 is rechecked even if DQ5 = “1” because DQ6 may stop toggling at the same time as DQ5 changing to “1”.
Pass
Figure 5. Toggle Bit Algorithm
16Am28F512A
18880C-10
CE#
t
OEH
WE#
OE#
Data
DQ0–DQ7
Note:
*DQ6 stops toggling (The device has completed the Embedded operation.)
DQ6 = DQ6 =
Figure 6. AC Waveforms for Toggle Bit during Embedded Algorithm Operations
*
t
OE
DQ6
Stop Toggling
DQ0–DQ7
Valid
18880C-11
DQ5
Exceeded Timing Limits
DQ5 will indicate if the program or erase time has
exceeded the specified limits. This is a failure condition and the device may not be used again (internal
pulse count exceeded). Under these conditions DQ5
will produce a “1.” The program or er ase cycle was not
successfully completed. Data# Polling is the only operating function of the de vice under this conditi on. The
CE# circuit will partially power down the device under
these conditions (to approximately 2 m A). The OE#
and WE# pins will control the output disable functions
as described in the Command Definitions table in the
corresponding device data sheet.
Parallel Device Erasure
The Embedded Erase algorithm greatly simplifies parallel device erasure. Sinc e the erase process is internal
to the device, a single eras e command can be given to
multiple devices concurrently. By implementing a parallel erase algorithm, total erase time may be minimized.
Note that the Flash memories may erase at different
rates. If this is the case, when a device is completely
erased, use a masking code to prevent further erasure
(over-erasure). The other de vices will continue t o erase
until verified. The masking code applied could be the
read command (00h).
Power-Up/Power-Down Sequence
The device powers-up in the Read only mode. Power
supply sequencing is not required. Note that if V
1.0 Volt, the voltage difference between V
and V
PP
CC
≤
CC
should not exceed 10.0 Volts. Also, the device has a
rise V
rise time and fall time specification of 500 ns
PP
minimum.
Reset Command
The Reset command initializes the Flash memory device to the Read mode. In addition, it also provides the
user with a safe method to abor t any device operation
(including program or erase).
The Reset must be written two cons ecutive times after
the Setup Program command (10h or 50h). This will
reset the device to the Read mode.
Following any other Flash comm and, write the Reset
command once to the device. This wi ll safely abort any
previous operation and initializ e the de vice to the Read
mode.
The Setup Program command (10h or 50h) is the only
command that requires a two-sequence reset cycle. The
first Reset command is interpreted as program data.
However , FFh data is considered as null data during programming operations (memor y cells are only programmed from a logica l “1" to “0"). The second Reset
command safely aborts the programming operation and
resets the device to the Read mode.
Memory contents are not altered in any case.
Am28F512A17
This detailed information i s for your reference. It may
prove easier to always issue the Reset command two
consecutive times. This elim inates the need to deter mine if you are in the Setup Program state or not.
In-System Programming Considerations
Flash memories can be programmed in-system or in a
standard PROM programmer. The device may be soldered to the circuit board upon receipt of shipment and
programmed in-system. Alternatively, the device may
initially be programmed in a PROM programmer prior
to soldering the device to the circuit board.
Auto Select Command
AMD’s Flash memories are designed for use in applications where the local CPU alters memory contents.
In order to correctly program any Flash memor ies
in-system, manufacturer and device codes must be
accessible while the device resides in the target
system. PROM programmers typically access the signature codes by r aising A9 to a hig h voltage . How ev er ,
multiplexing high voltage onto address lines is not a
generally desired system design practice.
The device contains an Auto Select operation to supplement traditional PROM programming methodologies.
The operation is initiated by writing 80h or 90h into the
command register. Following this c ommand, a read
cycle address 0000h retrieves the manufacturer code of
01h (AMD). A read cycle from address 0001h returns
the device code (see the Auto Select Code table of the
corresponding device data sheet). To terminate the operation, it is necessary to write another valid command,
such as Reset (00h or FFh), into the register.
18Am28F512A
ABSOLUTE MAXIMUM RATINGS
Storage Temperature . . . . . . . . . . . . –65°C to +150°C
with Power Applied. . . . . . . . . . . . . .–55°C to + 125°C
Voltage with Respect To Ground
All pins except A9 and V
(Note 1) . . . . . . . . . . . . . . . . . . . . . . .–2.0 V to +7.0 V
VCC (Note 1). . . . . . . . . . . . . . . . . . . .–2.0 V to +7.0 V
(Note 2). . . . . . . . . . . . . . . . . . . .–2.0 V to +14.0 V
A9
(Note 2). . . . . . . . . . . . . . . . . . .–2.0 V to +14.0 V
V
PP
Output Short Circuit Current (Note 3) . . . . . . 200 mA
Notes:
1. Minimum DC voltage on input or I/O pins is –0.5 V. During
voltage transitions, inputs may overshoot V
for periods of up to 20 ns. Max imum DC voltage o n inp ut
and I/O pins is V
input and I/O pins may overshoot to V
periods up to 20ns.
2. Minimum DC inpu t voltage on A9 a nd V
During voltage tran sitions, A9 and V
V
to –2.0 V for periods of up to 20 ns. Maximum DC
SS
input voltage on A9 and V
overshoot to 14.0 V for periods up to 20 ns.
3. No more than one output shorted to ground at a time.
Duration of the short circuit should not be greater than
one second.
Stresses above those listed under “Abso lute Maximum Ratings” may cause per mane nt dam age to the device. This is a
stress rating only; fun ctio nal ope ration of t he d evice at these
or any other condition s above those indicated in the operational sections of this specification is not implied. Exposure of
the device to absolute maximum rating conditions for
extended periods may affect device reliability.
PP
to –2.0 V
SS
+ 0.5 V. During voltage transitions,
CC
is +13.0 V which may
PP
+ 2.0 V for
CC
pins is –0.5 V.
PP
may overshoot
PP
OPERATING RANGES
Commercial (C) Devices
Ambient Temperature (T
Industrial (I) Devices
Ambient Temperature (T
Extended (E) Devices
Ambient Temperature (TA) . . . . . . . .–55°C to +125°C
Supply Voltages
V
CC
. . . . . . . . . . . . . . . . . . . . . . . +4.50 V to +5.50 V
V
CC
VPP Voltages
Read . . . . . . . . . . . . . . . . . . . . . . . . –0.5 V to +12.6 V
Program, Erase , and Verify. . . . . . +11.4 V to +12.6 V
Operating ranges define those limits between which the
functionality of the device is guaranteed.
) . . . . . . . . . . .0°C to +70°C
A
) . . . . . . . . .–40°C to +85°C
A
Am28F512A19
MAXIMUM OVERSHOOT
V
+ 0.5 V
CC
+0.8 V
–0.5 V
2.0 V
V
–2.0 V
+ 2.0 V
CC
20 ns
20 ns
20 ns
Maximum Negative Input Overshoot
20 ns
20 ns20 ns
18880C-12
V
CC
18880C-13
Maximum Po sitive Input Overshoot
20 ns
14.0 V
13.5 V
+ 0.5 V
20 ns20 ns
18880C-14
Maximum VPP Overshoot
20Am28F512A
DC CHARACTERISTICS over operating range unless otherwise specified
TTL/NMOS Compatible
IOH = –2.5 mA, VCC = VCC Min 0.85 V
IOH = –100 µA, V
A9 Auto Select Vo ltag eA9 = V
= VCC Min VCC –0.4
CC
ID
CC
11.513.0V
V
A9 Auto Select CurrentA9 = VID Max, VCC = VCC Max550µA
V
during Read-Only
PPL
Operations
V
during Read/Write
PP
Operations
Note: Erase/Program are inhibited
when V
PP
= V
PPL
0.0VCC + 2.0 V
11.412.6V
V
LKO
Low VCC Lock-out Voltage3.23.7V
Notes:
1. Caution: The Am28F512A must not be removed from (or inserted into) a socket when V
the voltage difference between V
and VCC should not exceed 10.0 volts. Also, the Am28F512A has a VPP rise time and fall
PP
time specification of 500 ns minimum.
2. I
3. Maximum active power usage is the sum of I
is tested with OE# = VIH to simulate open outputs.
CC1
CC
and IPP.
4. Not 100% tested.
22Am28F512A
or VPP is applied. If VCC ≤ 1.0 volt,
CC
25
20
15
Active in mA
10
CC
I
5
0
0123456789101112
Frequency in MHz
55°C
0°C
25°C
70°C
125°C
18880B-15
Figure 7. Am28F512A—Average ICC Active vs. Frequency
TEST CONDITIONS
Device
Under
Test
C
L
Note: Diodes are IN3064 or equivalent
6.2 kΩ
= 5.5 V, Addressing Pattern = Minmax
V
CC
Data Pattern = Checkerboard
5.0 V
Test Condition- 70All others Unit
2.7 kΩ
18880C-16
Output Load1 TTL gate
Output Load Capacitance, C
(including jig capacitance)
Input Rise and Fall Times≤10ns
Input Pulse Levels0.0–3.00.45–2.4V
Input timing measurement
reference levels
Output timing measurement
reference levels
Table 6.Test Specifications
L
30100 pF
1.5 0.8, 2.0V
1.50.8, 2.0V
23Am28F512A
SWITCHING TEST WAVEFORMS
s
2.4 V
0.45 V
2.0 V
Test Points
0.8 V
Input
2.0 V
0.8 V
Output
AC Testing (all speed options except -70): Inputs are driven
at 2.4 V for a logic “1” and 0.45 V for a logic “0”. Input pulse
rise and fall times are
≤
10 ns.
3 V
1.5 V
0 V
Input
Test Points
Output
AC Testing for -70 devices: Inputs are driven at 3.0 V for a
logic “1” and 0 V for a logic “0”. Input pulse rise and fall time
are ≤10 ns.
SWITCHING CHARACTERISTICS over operating range unless otherwise specified
AC Characteristics—Read Only Operation
Parameter Symbols
t
AVAV
t
ELQV
t
AVQV
t
GLQV
t
ELQX
t
t
t
ACC
t
t
RC
CE
OE
LZ
Parameter Description
Read Cycle Time (Note 2)Min7090120150200ns
Chip Enable Access TimeMax7090120150200ns
Address Access TimeMax7090120150200ns
Output Enable Access TimeMax3535505555ns
Chip Enable to Output in Low Z
(Note 2)
Min00000ns
Am28F512A Speed Option s
1.5 V
18880C-17
UnitJEDECStandard-70-90-1 20-150-200
t
EHQZ
t
GLQX
t
GHQZ
t
AXQX
t
VCS
t
t
OLZ
t
t
DF
DF
OH
Chip Disable to Output in High Z
(Note 1)
Output Enable to Output in Low Z
(Note 2)
Output Disable to Output in
High Z (Note 2)
Output Hold from first of Address,
CE
#, or OE# Change (Note 2)
VCC Setup Time to Valid Read
(Note 2)
Notes:
1. Guaranteed by design not tested.
2. Not 100% tested.
Max2020303535ns
Min00000ns
Max2020303535ns
Min00000ns
Min5050505050µs
Am28F512A24
AC Characteristics—Write/Erase/Program Operations
Parameter Symbols
t
AVAV
t
AVWL
t
WLAX
t
DVWH
t
WHDX
t
OEH
t
GHWL
t
ELWLE
t
WHEH
t
WLWH
t
WHWL
t
WHWH3
t
WHWH4
t
VPEL
t
t
t
t
t
t
CSE
t
t
t
WPH
WC
AS
AH
DS
DH
CH
WP
Am28F512A Speed Options
Parameter Description
UnitJEDECStandard-70-90-120-150-200
Write Cycle Time (Note 4)Min7090120150200ns
Address Setup TimeMin00000ns
Address Hold TimeMin4545506075ns
Data Setup TimeMin4545505050ns
Data Hold TimeMin1010101010ns
Output Enable Hold Time
for Embedded Algorithm only
Min1010101010µs
Read Recovery Time before Write Min00000µs
Chip Enable Embedded Algorithm
Embedded Erase Operation (Note 2)Typ55555ms
VPP Setup Time to Chip Enable LOW
(Note 4)
Min10010010010 0100ns
t
VCS
t
VPPR
t
VPPF
t
LKO
VCC Setup Time to Chip Enable LOW
(Note 4)
VPP Rise Time 90% V
VPP Fall Time 10% V
VCC < V
to Reset (Note 4)Min100100100100100ns
LKO
(Note 4)Min500500500500500ns
PPH
(Note 4)Min500500500500500ns
PPL
Min5050505050µs
Notes:
1. Read timing characteristics during read/write operations are the same as during read-only operations. Refer to AC
Characteristics for Read Only operations.
2. Embedded Program Operation of 14 µs consists of 10 µs program pulse and 4 ms write recovery before read. This is the
minimum time for one pass through the programming algorithm.
3. Embedded Erase Operation of 5 sec consists of 4 sec array pre-programming time and one sec array erase time. This is a
typical time for one embedded erase operation.
4. Not 100% tested.
25Am28F512A
KEY TO SWITCHING WAVEFORMS
WAVEFORMINPUTSOUTPUTS
Don’t Care, Any Change PermittedChanging, State Unknown
Does Not ApplyCenter Line is High Impedance State (High Z)
SWITCHING WAVEFORMS
Steady
Changing from H to L
Changing from L to H
Addresses
# (E#)
CE
OE
# (G#)
WE
# (W#)
Data (DQ)
5.0 V
V
CC
0 V
Power-up, Standby
t
VCS
High ZHigh Z
Device and
Address Selection
Outputs
Enabled
Data
Valid
Addresses Stable
t
(tRC)
AVAV
t
WHGL
t
(tOE)
GLQV
t
(tCE)
ELQV
t
AXQX (tOH
t
ELQX
(tLZ)
t
GLQX
(t
)
OLZ
Output Valid
t
(t
ACC
)
AVQV
Figure 9. AC Waveforms for Read Operations
Standby, Power-down
t
EHQZ
(t
)
DF
t
GHQZ
(tDF)
)
18880C-18
Am28F512A26
SWITCHING WAVEFORMS
Addresses
CE
OE#
WE#
Data
V
CC
Embedded
Erase Setup
t
WC
#
t
GHWL
t
WP
t
CSE
t
VCS
t
DS
30h
Embedded
Erase
t
AS
t
WPH
EraseStandby
t
AH
t
WHWH3 OR 4
t
DH
30h
Data# Polling
DQ7#
DQ7#
Read
t
RC
t
t
DF
OH
t
OE
t
CE
V
PP
t
VPEL
Note:
DQ7
#
is the complement of the data written to the device.
Figure 10. AC Waveforms for Embedded Erase Operation
18880C-19
27Am28F512A
SWITCHING WAVEFORMS
Addresses
CE
OE#
WE#
Data
V
CC
t
GHWL
Embedded
t
WPH
Program
PA
t
AS
t
AH
D
IN
t
WHWH3 OR 4
Data# Polling
PA
DQ7#
DQ7#DOUT
Read
t
RC
t
t
OE
t
CE
DF
t
OH
Embedded
Program Setup
t
WC
#
t
WP
t
CSE
t
DH
50h
t
VCS
t
DS
V
PP
Notes:
1. D
is data input to the device.
IN
#
2. DQ7
3. D
is the complement of the data written to the device.
is the data written to the device.
OUT
t
VPEL
Figure 11. AC Waveforms for Embedded Programming Operation
18880C-20
Am28F512A28
AC CHARACTERISTICS—WRITE/ERASE/PROGRAM OPERATIONS
Alternate CE
Parameter Symbols
t
AVAV
t
AVEL
t
ELAX
t
DVEH
t
EHDX
t
OEH
t
GHEL
t
WLEL
t
EHWK
t
ELEH
t
EHEL
t
EHEH3
t
EHEH4
t
VPEL
t
t
t
t
t
t
t
t
t
CPH
WC
AS
AH
DS
DH
WS
WH
CP
# Controlled Writes
Am28F512A Speed Options
Parameter Description
Write Cycle Time (Note 4)Min7090120150200ns
Address Setup TimeMin00000ns
Address Hold TimeMin4545506075ns
Data Setup TimeMin4545505050ns
Data Hold TimeMin1010101010ns
Output Enable Hold Time
for Embedded Algorithm only
Read Recovery Time before WriteMin00000ns
WE# Setup Time by CE#Min00000ns
WE# Hold TimeMin00000ns
Write Pulse WidthMin6565708080ns
Write Pulse Width HIGHMin2020202020ns
Embedded Programming Ope ration
(Note 2)
Embedded Erase Operation (Note 3)Typ55555sec
VPP Setup Time to Chip Enable LOW
(Note 4)
Min1010101010µs
Min1414141414µs
Min100100100100100ns
UnitJEDECStandard-70-90-120-150-200
t
VCS
t
VPPR
t
VPPF
t
LKO
VCC Setup Time to Chip Enable LOW
(Note 4)
VPP Rise Time 90% V
VPP Fall Time 10% V
VCC < V
to Reset (Note 4)Min100100100100100ns
LKO
(Note 4)Min500500500500500ns
PPH
(Note 4)Min500500500500500ns
PPL
Min5050505050µs
Notes:
1. Read timing characteristics during read/write operations are the same as during read-only operations. Refer to AC
Characteristics for Read Only operations.
2. Embedded Program Operation of 14 µs consists of 10 µs program pulse and 4 ms write recovery before read. This is the
minimum time for one pass through the programming algorithm.
3. Embedded Erase Operation of 5 sec consists of 4 sec array pre-programming time and one sec array erase time. This is a
typical time for one embedded erase operation.
4. Not 100% tested.
29Am28F512A
SWITCHING WAVEFORMS
Addresses
CE
OE#
WE#
Data
V
CC
Embedded
Program Setup
t
WC
#
t
GHEL
t
CP
t
WS
50h
t
DS
Embedded
Program
t
CPH
Data# Polling
DQ7#
PA
DQ7#
D
OUT
PA
t
AS
t
AH
t
EHEH3 OR 4
t
DH
D
IN
V
PP
t
VPEL
Notes:
1. D
is data input to the device.
IN
#
2. DQ7
3. D
is the complement of the data written to the device.
is the data written to the device.
OUT
Figure 12. AC Waveforms for Embedded Programming Operation Using CE# Controlled Writes
2. Maximum time specified is lower than worst case. Worst case is derived from the Embedded Algorithm internal counter which
allows for a maximum 6000 pulses for both program and erase operations. Typical worst case for program and erase is
significantly less than the actual device limit.
3. Typical worst case = 84 µs. DQ5 = “1” only after a byte takes longer than 96 ms to program.
LATCHUP CHARACTERISTICS
ParameterMinMax
Input Voltage with respect to V
Input Voltage with respect to V
Current–100 mA+100 mA
on all pins except I/O pins (Including A9 and VPP)–1.0 V13.5 V
SS
on all pins I/O pins–1.0 VVCC + 1.0 V
SS
Includes all pins except V
. Test conditions: VCC = 5.0 V, one pin at a time.
Note: Sampled, not 100% tested. Test conditions TA = 25°C, f = 1.0 MHz.
DATA RETENTION
ParameterTest ConditionsMinUnit
Minimum Pattern Data Retention Time
150°C10Years
125°C20Years
31Am28F512A
PHYSICAL DIMENSIONS
PD032—32-Pin Plastic DIP (measured in inches)
1.640
1.670
.120
.160
32
.140
.225
Pin 1 I.D.
.045
.065
.005 MIN
.090
.110
.016
.022
17
.530
.580
16
0°
10°
SEATING PLANE
.015
.060
PL032—32-Pin Plastic Leaded Chip Carrier (measured in inches)
.485
.495
.009
.015
.125
.140
.080
.095
SEATING
PLANE
.013
.021
.050 REF.
SIDE VIEW
.585
.595
.447
.453
Pin 1 I.D.
.547
.553
.026
.032
TOP VIEW
.600
.625
.009
.015
.630
.700
16-038-S_AG
PD 032
EC75
5-28-97 lv
.042
.056
.400
REF.
.490
.530
16-038FPO-5
PL 032
DA79
6-28-94 ae
Am28F512A32
PHYSICAL DIMENSIONS
TS032—32-Pin Standard Thin Small Outline Package (measured in millimeters)
0.95
1.05
Pin 1 I.D.
1
7.90
8.10
0.50 BSC
1.20
MAX
18.30
18.50
19.80
20.20
0.05
0.15
0.08
0.20
0.10
0°
5°
0.50
0.70
0.21
16-038-TSOP-2
TS 032
DA95
3-25-97 lv
33Am28F512A
PHYSICAL DIMENSIONS
TSR032—32-Pin Reversed Thin Small Outline Package (measured in millimeters)
0.95
1.05
Pin 1 I.D.
1
7.90
8.10
0.50 BSC
18.30
18.50
19.80
20.20
1.20
MAX
0°
5°
DATA SHEET REVISION SUMMARY FOR AM28F512A
Revision C
Deleted -75, -95, and -250 speed options. Matched f ormatting to other current data sheets.
Revision C+1
Programming In A PROM Programmer
Deleted the paragraph “(R efer to the AUTO SELEC T
paragraph in the ERASE, PROGRAM, and READ
MODE section for programming the Flash memory device in-system).”
Revision C+2
Product Selector Guide
Corrected maximum access time for -200 to 200 ns.
Connection Diagrams
On standard TSOP, corrected pin 9 to V
to NC. On reverse TSOP, corrected pin 23 to NC and
pin 24 to V