AMD Advanced Micro Devices AM28F010-70PC, AM28F010-70JIB, AM28F010-70JI, AM28F010-70JEB, AM28F010-70JE Datasheet

...
FINAL
Am28F010
1 Megab it (128 K x 8-B it) CMOS 12.0 Volt, Bulk Erase Flash Memory

DISTINCTIVE CHARACTERISTICS

High performance
— 70 ns maximum access time
CMOS Low power consumption
— 30 mA maximum active current — 100 µA maximum standby current — No data retention power consumption
Compatible with JEDEC-standard byte-wide
32-Pin EPROM pinouts
— 32-pin PDIP — 32-pin PLCC — 32-pin TSOP
10,000 write/erase cycles minimum
Write and erase voltage 12.0 V ±5%
Latch-up protected to 100 mA
from –1 V to V
CC
+1 V
Flasherase™
Electrical Bulk Chip-Erase
— One second typical chip-erase
Flashrite™ Programming
— 10 µs typical byte-program — Two seconds typical chip program
Command register architecture for microprocessor/microcontroller compatible write interface
On-chip address and data latches Advanced CMOS flash memory technology
— Low cost single transistor memory cell
Automatic write/erase pulse stop timer

GENERAL DESCRIPTION

The Am28F010 is a 1 Megabit Flash memory orga­nized as 128 Kbytes of 8 bits each. AMD’s Flash mem­ories offer the most cost-effective and reliable read/ write non-volatile random access memory. The Am28F010 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 Am28F010 is erased when shipped from the factory.
The standard Am28F010 offers acc ess times as f ast as 70 ns, allowing operation of high-speed microproces­sors without wait states. To eliminate bus contention, the Am28F010 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 Am28F010 uses a comman d register to manage t his functionality, while maintainin g a JEDEC Fla sh Stan­dard 32-pin p inout. The command r egister allows for 100% TTL level control inputs and fixed power supply levels during erase and programming, while maintain­ing maximum EPROM compatibility.
AMD’s Flash technology reliably stores memory co n­tents ev en after 10,000 erase and pr og r am cycl es . The AMD cell is d esigned t o optimize the erase and pro­gramming mechanis ms. In additi on, the com bination of advanced tunnel oxide processing and low internal electr ic fields for era se and p rogramming o peration s produc es reliable cycling. Th e Am28F010 uses a
12.0 V±5% V Flasherase
high voltage input to perform the
PP
and Flashrite algorithms.
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
CC
+1 V.
The Am28F010 is byte prog rammab le using 10 ms pro­gramming pulses in accordance with AMD’s Flashrite programming algorithm. The typical room temperature programming tim e of the Am 28F010 is t wo seconds. The entire chip i s bulk erased usi ng 10 ms erase pulses according to AMD’s Flasherase alrogithm. Typical era­sure at room temperature is accomplished in less than one second. The windowed package and the 15–20
Publicatio n# Issue Date:
Rev: HAmendm ent/
11559
+2
minutes required for EPROM erasure using ultra-violet light are eliminated.
Commands are written to the command register using standard mi cro proces sor wr i te ti ming s. Re gist er con­tents serve as inputs to an inter nal state-mac hine which controls the erase and programming circuitry. During write cycles, the comman d register inter nally latches address and data needed for the programming and erase o peration s. For system desi gn simplif ica­tion, the Am28F010 is designed to support either WE# or CE# controlle d writes. During a system write cycle, addresses are la tched on the falling edg e of WE# or CE# whichever occurs last. Data is latched on the ris-

BLOCK DIAGRAM

V
CC
V
SS
V
PP
Erase Voltage
ing edge of WE# or CE# whichever occurs first. To simplify the following discussion, the WE# pin is used as the write cycle control pin throughout the rest of this text. All se tup an d hold times are w ith res pect to the WE# signal.
AMD’s Flash technology combines years of EPROM and EEPROM ex perience to produce the highest le vels of quality, reliability, and cost effectiveness. The Am28F0 10 electri cally eras es all bits simultane ously using Fowler-Nordheim tunneling. The bytes are pro­grammed one byte at a time using the EPROM pro­gramming mechanism of hot electron injection.
DQ0–DQ7
Input/Output
Switch
Buffers
WE
CE OE
Low V
Detector
A0–A16
#
# #
CC
State
Control
Command
Register
Program/Erase
Pulse Timer

PRODUCT SELECTOR GUIDE

Program
Voltage Switch
To Array
Chip Enable
Output Enable
Logic
Y-Decoder
X-Decoder
Address Latch
Data
Latch
Y-Gating
1,048,576 Bit
Cell Matrix
11559H-1
Family Part Number Speed Options (V Max Access Time (ns) 70 90 120 150 200
(E#) Access (ns) 70 90 120 150 200
CE
#
(G#) Access (ns) 35 35 50 55 55
OE
#
= 5.0 V ± 10%)
CC
-70 -90 -120 -150 -200
Am28F010
2 Am28F010

CONNECTION DIAGRAMS

V
PP
A16 A15 A12
A7 A6 A5 A4 A3 A2 A1 A0
DQ0 DQ1
DQ2 V
SS
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16
PDIP
32 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17
V
CC
WE# (W#) NC A14 A13 A8 A9 A11 OE# (G#) A10 CE# (E#) DQ7 DQ6
DQ5 DQ4 DQ3
A7 A6 A5
A4 A3 A2 A1 A0
DQ0
5 6 7
8 9 10 11 12 13
14
A12
4
DQ1
15
A15
3
DQ2
PLCC
A16
2
17
SS
V
NC
VCCWE# (W#)
31 30
1
32
19 2016
18
DQ4
DQ3
DQ5
NC
29 28 27
26 25 24 23 22 21
DQ6
A14 A13
A8
A9 A11 OE# (G#)
A10 CE# (E#) DQ7
Note: Pin 1 is marked for orientation.
11559H-2
11559H-3
Am28F010 3
CONNECTION DIAGRAMS (continued)
A9 A8
CC
A7 A6 A5 A4
SS
1 2 3 4 5 6 7
#
8 9 10 11 12 13 14 15 16
32-Pin TSOP—Sta ndard Pinout
#
1 2
#
3 4 5 6 7 8 9 10 11 12 13 14 15 16
A11
A13 A14
NC
WE
V
NC A16 A15 A12
OE
A10
CE
D7 D6 D5 D4 D3
V
D2 D1 D0 A0 A1 A2 A3
TSOP
32 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17
32 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17
OE A10 CE D7 D6 D5 D4 D3 V
SS
D2 D1 D0 A0 A1 A2 A3
A11 A9 A8 A13 A14 NC WE V
CC
NC A16 A15 A12 A7 A6 A5 A4
# #
#
32-Pin TSOP—Reverse Pinout

LOGIC SYMBOL

17
A0–A16
DQ0–DQ7
CE
(E#)
#
OE# (G#) WE# (W#)
4 Am28F010
11559H-4
8
11559H-5
ORDERING INFORMATION Standard Products
AMD standard pro ducts are av ailab le i n several packages and op erating r ange s. The or der n umber (Valid Combination) is f ormed by a combination of:
AM28F010 -70 J C
DEVICE NUMBER/DESCRIPTION
Am28F010 1 Megabit (128 K x 8-Bit) CMOS Flash Memory
B
OPTIONAL PROCESSING
Blank = Standard Processing B=Burn-In
Contact an AMD representative for more information.
TEMP ERATURE RANGE
C = Commercial (0°C to +70°C) I = Industrial (–40°C to +85°C) E = Extended (–55°C to +125°C)
PACKA GE TYPE
P = 32-Pin Plastic DIP (PD 032) J = 32-Pin Rectangular Plastic Leaded Chip
Carrier (PL 032)
E = 32-Pin Thin Small Outline Package (TSOP)
Standard Pinout (TS 032)
F = 32-Pin Thin Small Outline Package (TSOP)
Reverse Pinout (TSR032)
SPEED OPTION
See Product Selector Guide and Valid Combinations
AM28F010-70 AM28F010-90 AM28F010-120 AM28F010-150 AM28F010-200
Valid Combinations
PC, PI, PE,
JC, JI, JE,
EC, EI, EE,
FC, FI, FE
Valid Combinations
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.
Am28F010 5
PIN DESCRIPTION A0–A16
A
ddress Inputs for memory locations. Internal latches
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-co rresponding pin is not connecte d internally to the die.

OE# (G#)

Output Enable active lo w input gates the outputs of the device through the data buffers dur ing memo ry rea d cycles. Output Enable is high during command sequencing and program/erase operations.
V
CC
Po wer supply f or de vice operation. (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 alter the mem­ory array contents . Memory contents cannot be alter ed
≤ V
when V
V
SS
Ground
PP
CC
+2 V.

WE# (W#)

Write Enable active l ow 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 la tched on the rising edge of the pulse. Write E nable high inhibits writing to the device.
6 Am28F010

BASIC PRINCIPLES

The device use s 100% TTL-l evel control inputs to manage the command 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 memor y and operate s like a standar d EPROM. The control inputs still manage traditional read, standby, output disable, and Auto select modes.

Command Register

The command register is enabled only when high volt­age is applied to the V gramming operat ions are only acce ssed via the register. In addition, 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 writ ten using stan­dard microp rocessor w rite timin gs. The re gister con­trols an internal state machine that manages all device operations. For syst em desig n simplificat ion, the de ­vice is designed to support either WE# or CE# con­trolled writes. During a system write cycle, addresses are latched on the falling edge of WE# or 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 Er as e/Progr am Ope ra ti on s

Flasherase™ Sequence

A multiple step command seq uence is require d to erase the Flash device (a two-cyc le Erase command and repeated one cycle verify commands).
Note: The Flash memory array must be completely programmed to 0’s prior to erasure. Refer to the Flashrite™ Programming Algorithm.
1. Erase Setup: Write the Setup Erase command to the command register.
2. Erase: Write the Erase command (same as Setup Erase comman d) to t he comman d register again. The second command initiates the er ase operation. The system software routine s must now time-ou t the erase pulse wid th (10 ms) prior t o issuing the Erase-verify command. An integrated stop timer prevents any possibility of overerasure.
3. Erase-Verify: Wr ite the Erase-verify command to the command register. This command terminates the erase ope ration. After the erase op eration, each byte of the array must be verified. Address in-
formation must be supplied with the Erase-verify command. This command verifies the mar gin and outputs the addressed byte in order to compare the array data with FFh data (Byte erased). After successful data verification the Erase-verify command is written again with new address infor­mation. Each byte of t he a rray is sequentially veri­fied in this manner.
If data of the addressed location is not verified, the Erase sequence is repeated until the entire array is successfully verified or the sequence is repeated 1000 times.
Flashrite
A three step command sequence (a two- cycle Progr am command and one cycle Verify command) is required to program a byte of the Flash arra y. Refer to the Flash­rite
1. Program Setup: Write the Setup Program com-
2. Program: Write the Program command to the com-
3. Program-Verify: Write the Program-verify com-
If data is not verified successfully, the Program se­quence is repeat ed until a success ful comp arison is verified or the sequence is repeated 25 times.
Programming Sequence
Algorithm.
mand to the command register.
mand register with the appropriate Address and Data. The system software routines m ust no w time­out the program pulse width (10 µs) prior to issuing the Progr am-verify co mmand. An in tegrated sto p timer prevents any possibility of overprogramming.
mand to the command register. This command ter­minates the programming operation. In addition, this command verifies the margin and ou tputs the byte just progr ammed in or der to compare the arr a y data with the original data programmed. After suc­cessful data verification, the programming se­quence is initiated again f or the ne xt b yte address to be programmed.

Data Protection

The device is designed to off er protection against acci­dental erasure or programming caused by spurious system lev el signals that ma y exist during power transi­tions. The de vic e power s up i n its read only s tate. A lso, with its co ntrol reg ister ar chitectu re, alteration of the memory contents only occurs after successful comple­tion of specific command sequences.
The device also incorporates several features to pre­vent inadv ertent write cycles resulting fromV up and power-down transitions or system noise.
power-
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
Am28F010 7
VCC < V voltages). When V disabled, al l internal pro gram/erase circuits are disabled, and the device resets to the read mode. The device ignores all writes until V must ensure that the control pins are in the correct logic state when V

Write Pulse “Glitch” Protection

Noise pulses of less than 10 ns (typical) on OE#, CE# or WE# will not initiate a write cycle.
(see DC C haracteristics section for
LKO
CC
> V
CC
< V
LKO
, the command register is
LKO
> V
CC
to prev ent uni nitentional writes.
LKO
. The user

Logical Inhibit

Writing i s inhibi ted by holding any one of OE# = VIL, CE#
or WE# = VIH. To initiate a write cycle CE# and
= V
IH
WE# must be a logical zero while OE# is a logical one.

Power-Up Write Inhibit

Power-up of the device with WE# = CE# = VIL and OE# = V edge of WE # . The in te rn al st at e ma chine is a ut oma t­ically reset to the read mode on power-up.
will not accept commands on the rising
IH
FUNCTIONAL DESCRIPTION Description of User Modes
Table 1. Am28F010 Device Bus Operations
Operation CE# (E#)OE# (G#)WE# (W#)
V
PP
(Note 1) A0 A9 I/O
Read-Only
Read/Write
Read V Standby V Outp ut Disable V Auto-Select Manufacturer
Code (Note 2) Auto-Select Device Code
(Note 2)
Read V
Standby (Note 5) V Outp ut Disable V
Write V
IL
IH
IL
V
IL
V
IL
IL
IH
IL
IL
V
IL
XXV
V
IH
V
IL
V
IL
V
IL
XXV
V
IH
V
IH
XV
V
IH
V
IH
V
IH
V
IH
V
IH
V
IL
V
V
V
V
V
V
PPL
PPL
PPL
PPL
PPL
PPH
PPH
PPH
PPH
A0 A9 D
XXHIGH Z XXHIGH Z
V
IL
V
IH
VID
(Note 3)
VID
(Note 3)
A0 A9
XXHIGH Z XXHIGH Z
A0 A9
Legend:
X = Don’t care, where Don’t Care is either V
of V
. 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, connect e d with a resistor to gr ound, 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 v oltage 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 < VID < 13.0 V. Minimum VID rise time and fall time (between 0 and VID voltages) is 500 ns.
4. Read operation with V
5. With V
at high voltage, the standby current is ICC + IPP (standby).
PP
6. Refer to Table 3 for vali d D
7. All inputs are Don’t Care unless otherwise stated, where Don’t Care is either V addresses except A9 and A0 must be held at V
8. If V
1.0 Volt, the voltage difference between VPP and VCC should not exceed 10.0 volts. Also, the Am28F010 has a VPP
CC
= V
PP
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
IL
rise time and fall time specification of 500 ns minimum.
OUT
CODE
(01h)
CODE
(A7h)
D
OUT
(Note 4)
D
IN
(Note 6)
8 Am28F010

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 regist er
CC

Read

The devic e functi ons as a read only memory when V < V
+ 2 V. The device has two control functions. 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 acce ss time t
is equal to the de lay from
ACC
stable addresses to valid output data. The chip enable access time t
is the delay from stable addresses and
CE
stable CE# to valid data at the output pins. The output enable access time is the del a y from the falling 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 mo des. The CMOS standby mode (CE # inp ut held a t V sumes less than 100 µA of current. TTL standby mode (CE# is held at V
) reduces the current requirements
IH
to less than 1mA. When in the sta ndby mode the out­puts are in a high impedance state, independent of the OE# input.
If the d evice is de select ed dur ing er asure, pr ogram­ming, or program/erase verification, the device will draw active current until the operation is terminated.
CC
±
0.5 V), con-

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 recei pt 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 purpose of automatically matching the device to be pro­grammed with its corresponding programming algo­rithm. Th is 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 may then be sequenced from the de vice outputs by toggling addr ess A address lin es 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 the de vi ce these tw o by tes are giv en in Table 2 below. All identifiers for manufacturer and device codes will exhibit odd parit y with the MSB (D Q7) de­fined as the parity bit.
(11.5 V to 13.0 V) on address A9. Two
ID
from VIL to VIH. All other
0
, and VPP must be
+ 2.0 V while using this Auto
CC
IL
) represents the manuf ac-
IL
) the device identifier
IH

Output Disable

Output from th e device is disabled when OE# is at a logic high level. When disa bled, output pins are in a high impedance state.
Table 2. Am28F010 Auto Select Code
Type A0 Code (HEX)
Manufactur er Code V Device Code V
IL
IH
01 A7
Am28F010 9

ERASE, PROGRAM, AND READ MODE

When VPP is equal to 12.0 V ± 5%, the command reg­ister is active. All functions are available. That is, the device can program, erase, rea d array or a utoselec t 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.
Refer to AC Write Characteri stics and the Erase/Pro­gramming Waveforms for specific timing parameters.

Command Definitions

The contents of th e command register default to 00 h (Read Mode) in the absence of high voltage applied to the V ory. High voltage on the V register . D e vic e operations are selected by writing spe­cific data codes into the command register. Table 3 de­fines these register commands.
pin. The device operates as a read only mem-
PP
pin enables the command
PP
The co mma nd r eg is ter does no t o cc upy an addressab le memory location. The register is a latch that stores the comman d, al on g wi th th e addr e ss and da ta in form at io n needed to execute the command. The register is written by bringing WE# and CE# to V
, while OE# is at VIH.
IL
Addres ses ar e latc hed on th e fa lli ng edge of WE#, while data is latch ed on the ri sing edge of the WE# pulse. Standard microprocessor write timings are used.
The device requires the OE# pin to be V
for write op-
IH
erations. This condition eliminates the possibility for bus contentio n during programmi ng operations. I n 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.

Read Command

Memory contents can be accessed via the read com­mand when V 00h into the command register . Standard micr oproces­sor read cycles access data from the memory. The de­vice will remain in th e read mode until t he 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
Ta ble 3. Am28F010 Command Definitions
First Bus Cycle Second Bus Cycle
Operation
Command (Note 4)
Read Memory Write X 00h/FFh Read RA RD Read Auto select Write X 80h or 90h Read 00h/01h 01h/A7h Erase Setup/Erase Write Write X 20h Write X 20h
(Note 1)
Address
(Note 2)
Data
(Note 3)
Operation
(Note 1)
Address
(Note 2)
Data
(Note 3)
Erase-Verify Write EA A0h Read X EVD Program Setup/Program Write X 40h Write PA PD Program-Verify Write X C0h Read X PVD Reset Write X FFh Write X FFh
Notes:
1. Bus operations are defined in Table 1.
2. RA = Address of the memory location to be read. EA = Address of the memory location to be read during erase-verify. PA = Address of the memory location to be programmed. X = Don ’t care.
#
Addresses are latched on the falling edge of the WE
3. RD = Data read from location RA during read operation. EVD = Data Read from location EA during erase-verify. PD = Data to be programmed at location PA. Data latched on the rising edge of WE PVD = Data read from location PA during program-verify. PA is latched on the Program command.
4. Refer to the appropriate section for algorithms and timing diagrams.
pulse.
#
.
10 Am28F010
FLASHERASE ERASE SEQUENCE Erase Setup
Erase Setup is the first of a two-cycle erase command. It is a command-only operation that stages the device for bulk chip erase. The array contents are not altered with this command. 20h is written to the command reg­ister in order to perform the Erase Setup operation.

Erase

The second two-cycle erase command initiates the bulk erase operation. You must write the Erase com­mand (20h) again to the register. The erase operation begins with the rising edge of the WE# pulse. The erase operation must be termina ted by writing a new command (Erase-verify) to the register.
This two step sequence of the Setup and Erase com­mands helps to ensure that memory contents are not accidentally erased. Also, chip erasure can only occur when high vol tage is applied to the V trol pins are in their proper state . In absence of this high voltage, memory contents cannot be altered. Refer to AC Erase Characteristics and Waveforms for specific timing parameters.
pin and all con-
PP
Note: The Flash memory device must be fully programmed to 00h data prior to erasure. This equalizes the charge on all memory cells ensuring reliable erasure.

Erase-Verify Command

The erase operation erases all bytes of the array in parallel. After the erase operation, all bytes must be sequentially verified. The E rase- verify operation is initi -
ated by writing A0h to the register . The byte address to be verified mus t be supp lied with t he comman d. Ad­dresses are latched on the falling edge of the WE# pulse or CE# pulse, whichever occurs later. The rising edge of the WE# pulse terminates the erase operation.

Margin Verify

During the Erase-verify operation, the device applies an internally generated margin voltage to the addressed byte. Reading FFh from the addressed byte indicates that all bits in the byte are properly erased.

Verify Next Address

You must write the Erase-verify command with the ap­propriate address to the register prior to verification of each address. Each new address is latched on the fall­ing edge of WE# or CE# pulse, whichev er occurs later. The process continues for each byte in the memory array until a byte does n ot retur n FFh dat a or all the bytes in the array are accessed and verified.
If an address is not verified to FFh data, the entire chip is erased again (refe r to Erase Setup/Erase). Erase verification then resumes at the address that failed to verify. Erase is complet e when all bytes in the array have been verified. The device is now ready to be pro­grammed. At this point, the v erific ation operation is ter­minated by writing a valid command (e.g. Program Setup) to the command register. Figure 1 and Table 4, the Flasherase commands and bus operations are com bined to per­form electrical erasure . Refer to AC Er ase Char acteris­tics and Waveforms for specific timing parameters.
electrical erase algorithm, illustr ate how
Am28F010 11
Loading...
+ 24 hidden pages