ETC 24AA65T/SM

24AA65
64K 1.8V I2C™ Smart Serial™ EEPROM
FEATURES
PDIP
A0
1
8
VCC
A1
2
7
NC
A2
3
6
SCL
VSS
4
5
SDA
A0
1
8
VCC
A1
2
7
NC
A2
3
6
SCL
VSS
4
5
SDA
SOIC
24AA65
BLOCK DIAGRAM
A0 A1 A2
I/O
CONTROL
LOGIC
MEMORY
CONTROL
LOGIC
HV GENERATOR
XDEC
EEPROM
ARRAY
PAGE LATCHES
DESCRIPTION
The Microchip Technology Inc. 24AA65 is a “smart” 8K
x 8 Serial Electrically Erasable PROM. This device has
been developed for advanced, low power applications
such as personal communications, and provides the
systems designer with flexibility through the use of many
new user-programmable features. It is capable of operation down to 1.8V, the end-of-life voltage for 2 “AA” battery cells for most popular battery technologies.The
24AA65 offers a relocatable 4K bit block of ultra-highendurance memory for data that changes frequently.
The remainder of the array, or 60K bits, is rated at
1,000,000 ERASE/WRITE (E/W) cycles guaranteed.
The 24AA65 features an input cache for fast write loads
with a capacity of eight pages, or 64 bytes. This device
also features programmable security options for E/W
protection of critical data and/or code of up to fifteen 4K
blocks. Functional address lines allow the connection of
24AA65
• Voltage operating range: 1.8V to 6.0V
- Peak write current 3 mA at 6.0V
- Maximum read current 150 µA at 6.0V
- Standby current 1 µA typical
• Industry standard two wire bus protocol I2C
compatible
• 8 byte page, or byte modes available
• 2 ms typical write cycle time, byte or page
• 64-byte line input cache for fast write loads
• Up to 8 devices may be connected to the same
bus for up to 512K bits total memory
• 100 kHz (1.8V) and 400 kHz (5.0V) compatibility
• Programmable block security options
• Programmable endurance options
• Schmitt trigger, filtered inputs for noise suppression
• Output slope control to eliminate ground bounce
• Self-timed ERASE and WRITE cycles
• Power on/off data protection circuitry
• Endurance:
- 10,000,000 E/W cycles guaranteed for a High
Endurance Block
- 1,000,000 E/W cycles guaranteed for a Standard Endurance Block
• Electrostatic discharge protection > 4000V
• Data retention > 200 years
• 8-pin PDIP/SOIC packages
• Temperature ranges
- Commercial (C):
0°C to +70°C
PACKAGE TYPES
I/O
SDA
SCL
BUFFER
YDEC
VCC
VSS
SENSE AMP
R/W CONTROL
up to eight 24LC65's on the same bus for up to 512K bits
contiguous EEPROM memory. Advanced CMOS technology makes this device ideal for low-power non-volatile code and data applications. The 24AA65 is available
in the standard 8-pin plastic DIP and 8-pin surface
mount SOIC package.
I2C is a trademark of Philips Corporation.
Smart Serial is a trademark of Microchip Technology Inc.
 1998 Microchip Technology Inc.
DS21056H-page 1
24AA65
1.0
ELECTRICAL CHARACTERISTICS
1.1
Maximum Ratings*
PIN FUNCTION TABLE
Function
Name
VCC ..................................................................................7.0V
All inputs and outputs w.r.t. VSS ............... -0.6V to VCC +1.0V
Storage temperature ...................................... -65˚C to+150˚C
Ambient temp. with power applied................. -65˚C to +125˚C
Soldering temperature of leads (10 seconds) ............. +300˚C
ESD protection on all pins ..................................................≥ 4 kV
*Notice: Stresses above those listed under “Maximum Ratings”
may cause permanent damage to the device. This is a stress rating only and functional operation of the device at those or any
other conditions above those indicated in the operational listings
of this specification is not implied. Exposure to maximum rating
conditions for extended periods may affect device reliability.
TABLE 1-2:
TABLE 1-1:
A0,A1,A2
VSS
SDA
SCL
VCC
NC
User Configurable Chip Selects
Ground
Serial Address/Data I/O
Serial Clock
+1.8V to 6.0V Power Supply
No Internal Connection
DC CHARACTERISTICS
VCC = +1.8V to +6.0V
Commercial(C): Tamb = 0˚C to +70˚C
Parameter
A0, A1, A2, SCL and SDA pins:
High level input voltage
Low level input voltage
Hysteresis of Schmitt Trigger
inputs
Low level output voltage
Input leakage current
Output leakage current
Pin capacitance
(all inputs/outputs)
Operating Current
Symbol
Min
Max
Units
VIH
VIL
VHYS
.7 VCC
—
.05 VCC
—
.3 VCC
—
V
V
V
Note 1
VOL
—
.40
V
IOL = 3.0 mA
ILI
ILO
CIN, COUT
-10
-10
—
10
10
10
µA
µA
pF
ICC Write
ICC Read
—
—
—
3
150
5
2
mA
µA
µA
µA
VIN = .1V to VCC
VOUT = .1V to VCC
VCC = 5.0V (Note)
Tamb = 25˚C, Fclk = 1 MHz
VCC = 6.0V, SCL = 400 kHz
VCC = 6.0V, SCL = 400 kHz
VCC = 5.0V, SCL = SDA = VCC
VCC = 1.8V, SCL = SDA = VCC
A0, A1, A2 = VSS (Note)
Standby current
Conditions
Note: This parameter is periodically sampled and not 100% tested.
FIGURE 1-1:
BUS TIMING START/STOP
VHYS
SCL
THD:STA
TSU:STA
TSU:STO
SDA
START
DS21056H-page 2
STOP
 1998 Microchip Technology Inc.
24AA65
TABLE 1-3:
AC CHARACTERISTICS
Vcc = 1.8V - 6.0V Vcc = 4.5V - 6.0V
STD. MODE
FAST MODE
Symbol
Parameter
Min
Max
Min
Max
Units
Remarks
Clock frequency
Clock high time
Clock low time
SDA and SCL rise time
SDA and SCL fall time
START condition hold time
FCLK
THIGH
TLOW
TR
TF
THD:STA
—
4000
4700
—
—
4000
100
—
—
1000
300
—
—
600
1300
—
—
600
400
—
—
300
300
—
kHz
ns
ns
ns
ns
ns
START condition setup time
TSU:STA
4700
—
600
—
ns
Data input hold time
Data input setup time
STOP condition setup time
Output valid from clock
Bus free time
THD:DAT
TSU:DAT
TSU:STO
TAA
TBUF
0
250
4000
—
4700
—
—
—
3500
—
0
100
600
—
1300
—
—
—
900
—
ns
ns
ns
ns
ns
TOF
—
250
250
ns
TSP
—
50
20 +0.1
CB
—
(Note 2)
Time the bus must be
free before a new
transmission can start
(Note 1), CB ≤ 100 pF
50
ns
(Note 3
TWR
—
5
—
5
ms/
page
(Note 4)
Output fall time fro VIH min to
VIL max
Input filter spike suppression
(SDA and SCL pins)
Write cycle time
(Note 1)
(Note 1)
After this period the
first clock pulse is generated
Only relevant for
repeated START condition
Endurance
High Endurance Block
10M
—
10M
—
cycles 25°C, Vcc = 5.0V,
Rest of Array
1M
—
1M
—
Block Mode (Note 5)
Note 1: Not 100 percent tested. CB = total capacitance of one bus line in pF.
2: As a transmitter, the device must provide an internal minimum delay time to bridge the undefined region
(minimum 300 ns) of the falling edge of SCL to avoid unintended generation of START or STOP conditions.
3: The combined TSP and VHYS specifications are due to new Schmitt trigger inputs which provide improved
noise and spike suppression. This eliminates the need for a TI specification for standard operation.
4: The times shown are for a single page of 8 bytes. Multiply by the number of pages loaded into the write
cache for total time.
5: This parameter is not tested but guaranteed by characterization. For endurance estimates in a specific
application, please consult the Total Endurance Model which can be obtained on our website.
FIGURE 1-2:
BUS TIMING DATA
TF
TR
THIGH
TLOW
SCL
TSU:STA
THD:DAT
TSU:DAT
THD:STA
SDA
IN
TSP
TSU:STO
TBUF
TAA
TAA
SDA
OUT
 1998 Microchip Technology Inc.
DS21056H-page 3
24AA65
2.0
FUNCTIONAL DESCRIPTION
The 24AA65 supports a bidirectional two-wire bus and
data transmission protocol. A device that sends data
onto the bus is defined as transmitter, and a device
receiving data as receiver. The bus must be controlled
by a master device which generates the serial clock
(SCL), controls the bus access, and generates the
START and STOP conditions, while the 24AA65 works
as slave. Both master and slave can operate as transmitter or receiver but the master device determines
which mode is activated.
3.0
BUS CHARACTERISTICS
3.4
Data Valid (D)
The state of the data line represents valid data when,
after a START condition, the data line is stable for the
duration of the HIGH period of the clock signal.
The data on the line must be changed during the LOW
period of the clock signal. There is one clock pulse per
bit of data.
Each data transfer is initiated with a START condition
and terminated with a STOP condition. The number of
the data bytes transferred between the START and
STOP conditions is determined by the master device.
The following bus protocol has been defined:
3.5
• Data transfer may be initiated only when the bus
is not busy.
• During data transfer, the data line must remain
stable whenever the clock line is HIGH. Changes
in the data line while the clock line is HIGH will be
interpreted as a START or STOP condition.
Each receiving device, when addressed, is obliged to
generate an acknowledge after the reception of each
byte. The master device must generate an extra clock
pulse which is associated with this acknowledge bit.
Accordingly, the following bus conditions have been
defined (Figure 3-1).
3.1
Bus not Busy (A)
Both data and clock lines remain HIGH.
3.2
Start Data Transfer (B)
A HIGH to LOW transition of the SDA line while the
clock (SCL) is HIGH determines a START condition.
All commands must be preceded by a START condition.
3.3
Note:
Acknowledge
The 24AA65 does not generate any
acknowledge bits if an internal programming cycle is in progress.
A device that acknowledges must pull down the SDA
line during the acknowledge clock pulse in such a way
that the SDA line is stable LOW during the HIGH period
of the acknowledge related clock pulse. Of course,
setup and hold times must be taken into account. During reads, a master must signal an end of data to the
slave by NOT generating an acknowledge bit on the
last byte that has been clocked out of the slave. In this
case, the slave (24AA65) must leave the data line
HIGH to enable the master to generate the STOP condition.
Stop Data Transfer (C)
A LOW to HIGH transition of the SDA line while the
clock (SCL) is HIGH determines a STOP condition. All
operations must be ended with a STOP condition.
FIGURE 3-1:
SCL
DATA TRANSFER SEQUENCE ON THE SERIAL BUS
(A)
(B)
(D)
START
CONDITION
ADDRESS OR
ACKNOWLEDGE
VALID
(D)
(C)
(A)
SDA
DS21056H-page 4
DATA
ALLOWED
TO CHANGE
STOP
CONDITION
 1998 Microchip Technology Inc.
24AA65
3.6
Device Addressing
A control byte is the first byte received following the
start condition from the master device. The control byte
consists of a four bit control code, for the 24AA65 this
is set as 1010 binary for read and write operations. The
next three bits of the control byte are the device select
bits (A2, A1, A0). They are used by the master device
to select which of the eight devices are to be accessed.
These bits are in effect the three most significant bits of
the word address. The last bit of the control byte
defines the operation to be performed. When set to a
one a read operation is selected, when set to a zero a
write operation is selected. The next two bytes received
define the address of the first data byte (Figure 4-1).
Because only A12..A0 are used, the upper three
address bits must be zeros. The most significant bit of
the most significant byte is transferred first. Following
the start condition, the 24AA65 monitors the SDA bus
checking the device type identifier being transmitted.
Upon receiving a 1010 code and appropriate device
select bits, the slave device (24AA65) outputs an
acknowledge signal on the SDA line. Depending upon
the state of the R/W bit, the 24AA65 will select a read
or write operation.
Operation
Control
Code
Device Select
R/W
Read
Write
1010
1010
Device Address
Device Address
1
0
FIGURE 3-2:
READ/WRITE
SLAVE ADDRESS
1
0
FIGURE 4-1:
1
0
A2
R/W
A1
WRITE OPERATION
4.1
Byte Write
Following the start condition from the master, the control code (four bits), the device select (three bits), and
the R/W bit which is a logic low is placed onto the bus
by the master transmitter. This indicates to the
addressed slave receiver (24AA65) that a byte with a
word address will follow after it has generated an
acknowledge bit during the ninth clock cycle. Therefore
the next byte transmitted by the master is the highorder byte of the word address and will be written into
the address pointer of the 24AA65. The next byte is the
least significant address byte. After receiving another
acknowledge signal from the 24AA65 the master
device will transmit the data word to be written into the
addressed memory location. The 24AA65 acknowledges again and the master generates a stop condition. This initiates the internal write cycle, and during
this time the 24AA65 will not generate acknowledge
signals (Figure 4-1).
4.2
Page Write
The write control byte, word address and the first data
byte are transmitted to the 24AA65 in the same way as
in a byte write. But instead of generating a stop condition the master transmits up to eight pages of eight data
bytes each (64 bytes total) which are temporarily stored
in the on-chip page cache of the 24AA65. They will be
written from the cache into the EEPROM array after the
master has transmitted a stop condition. After the
receipt of each word, the six lower order address
pointer bits are internally incremented by one. The
higher order seven bits of the word address remain
constant. If the master should transmit more than eight
bytes prior to generating the stop condition (writing
across a page boundary), the address counter (lower
three bits) will roll over and the pointer will be incremented to point to the next line in the cache. This can
continue to occur up to eight times or until the cache is
full, at which time a stop condition should be generated
by the master. If a stop condition is not received, the
cache pointer will roll over to the first line (byte 0) of the
cache, and any further data received will overwrite previously captured data. The stop condition can be sent
at any time during the transfer. As with the byte write
operation, once the stop condition is received an internal write cycle will begin. The 64 byte cache will continue to capture data until a stop condition occurs or the
operation is aborted (Figure 4-2).
CONTROL BYTE
ALLOCATION
START
4.0
A
A0
BYTE WRITE
BUS ACTIVITY
MASTER
S
T
A
R
T
SDA LINE
S
BUS ACTIVITY
 1998 Microchip Technology Inc.
Word
Address (0)
Word
Address (1)
CONTROL
BYTE
S
T
O
P
DATA
P
0 0 0 0
A
C
K
A
C
K
A
C
K
A
C
K
DS21056H-page 5
24AA65
FIGURE 4-2:
BUS
ACTIVITY
MASTER
S
T
A
R
T
SDA LINE
S
PAGE WRITE (FOR CACHE WRITE, SEE FIGURE 8-2)
WORD
ADDRESS (1)
CONTROL
BYTE
WORD
ADDRESS (0)
S
T
O
P
DATA n + 7
DATA n
P
0 0 0 0
A
C
K
A
C
K
BUS
ACTIVITY
FIGURE 4-3:
A
C
K
A
C
K
A
C
K
CURRENT ADDRESS READ
BUS ACTIVITY
MASTER
S
T
A
R
T
SDA LINE
S
CONTROL
BYTE
S
T
O
P
DATA n
P
N
O
A
C
K
BUS ACTIVITY
A
C
K
FIGURE 4-4:
S
T
A
R
T
RANDOM READ
WORD
ADDRESS (1)
CONTROL
BYTE
SDA LINE S
BUS
ACTIVITY:
FIGURE 4-5:
BUS ACTIVITY
MASTER
S
T
A
R
T
WORD
ADDRESS (0)
0 0 0
CONTROL
BYTE
S
T
O
P
DATA n
P
S
A
C
K
A
C
K
N
O
A
C
K
A
C
K
A
C
K
SEQUENTIAL READ
CONTROL
BYTE
DATA n
DATA n + 1
DATA n + 2
S
T
O
P
DATA n + X
P
SDA LINE
BUS ACTIVITY
A
C
K
A
C
K
A
C
K
A
C
K
N
O
A
C
K
DS21056H-page 6
 1998 Microchip Technology Inc.
24AA65
5.0
READ OPERATION
Read operations are initiated in the same way as write
operations with the exception that the R/W bit of the
slave address is set to one. There are three basic types
of read operations: current address read, random read,
and sequential read.
5.1
Current Address Read
The 24AA65 contains an address counter that maintains the address of the last word accessed, internally
incremented by one. Therefore, if the previous access
(either a read or write operation) was to address n (n is
any legal address), the next current address read operation would access data from address n + 1. Upon
receipt of the slave address with R/W bit set to one, the
24AA65 issues an acknowledge and transmits the eight
bit data word. The master will not acknowledge the
transfer but does generate a stop condition and the
24AA65 discontinues transmission (Figure 4-3).
5.2
Random Read
Random read operations allow the master to access
any memory location in a random manner. To perform
this type of read operation, first the word address must
be set. This is done by sending the word address to the
24AA65 as part of a write operation (R/W bit set to 0).
After the word address is sent, the master generates a
start condition following the acknowledge. This terminates the write operation, but not before the internal
address pointer is set. Then the master issues the control byte again but with the R/W bit set to a one. The
24AA65 will then issue an acknowledge and transmit
the eight bit data word. The master will not acknowledge the transfer but does generate a stop condition
which causes the 24AA65 to discontinue transmission
(Figure 4-4).
5.3
5.4
Contiguous Addressing Across
Multiple Devices
The device select bits A2, A1, A0 can be used to
expand the contiguous address space for up to 512K
bits by adding up to eight 24LC65's on the same bus.
In this case, software can use A0 of the control byte as
address bit A13, A1 as address bit A14, and A2 as
address bit A15.
5.5
Noise Protection
The SCL and SDA inputs have filter circuits which suppress noise spikes to assure proper device operation
even on a noisy bus. All I/O lines incorporate Schmitt
triggers for 400 kHz (Fast Mode) compatibility.
5.6
High Endurance Block
The location of the high-endurance block within the
memory map is programmed by setting the leading bit
7 (S/HE) of the configuration byte to 0. The upper bits
of the address loaded in this command will determine
which 4K block within the memory map will be set to
high endurance. This block will be capable of
10,000,000 ERASE/WRITE cycles (Figure 8-1).
Note:
The High Endurance Block cannot be
changed after the security option has been
set. If the H.E. block is not programmed by
the user, the default location is the highest
block of memory.
Sequential Read
Sequential reads are initiated in the same way as a random read except that after the 24AA65 transmits the
first data byte, the master issues an acknowledge as
opposed to the stop condition used in a random read.
This acknowledge directs the 24AA65 to transmit the
next sequentially addressed 8 bit word (Figure 4-5).
Following the final byte transmitted to the master, the
master will NOT generate an acknowledge but will generate a stop condition.
To provide sequential reads the 24AA65 contains an
internal address pointer which is incremented by one at
the completion of each operation. This address pointer
allows the entire memory contents to be serially read
during one operation.
 1998 Microchip Technology Inc.
DS21056H-page 7
24AA65
5.7
Security Options
The 24AA65 has a sophisticated mechanism for writeprotecting portions of the array. This write protect function is programmable and allows the user to protect 015 contiguous 4K blocks. The user sets the security
option by sending to the device the starting block number for the protected region and the number of blocks
to be protected. All parts will come from the factory in
the default configuration with the starting block number
set to 15 and the number of protected blocks set to
zero. THE SECURITY OPTION CAN BE SET ONLY
ONCE.
To invoke the security option, a write command is sent
to the device with the leading bit (bit 7) of the first
address byte set to a 1 (Figure 8-1). Bits 1-4 of the first
address byte define the starting block number for the
protected region. For example, if the starting block
number is to be set to 5, the first address byte would be
1XX0101X. Bits 0, 5 and 6 of the first address byte are
disregarded by the device and can be either high or
low. The device will acknowledge after the first address
byte. A byte of don't care bits is then sent by the master,
with the device acknowledging afterwards. The third
byte sent to the device has bit 7 (S/HE) set high and bit
6 (R) set low. Bits 4 and 5 are don't cares and bits 0-3
define the number of blocks to be write protected. For
example, if three blocks are to be protected, the third
byte would be 10XX0011. After the third byte is sent to
the device, it will acknowledge and a STOP bit is then
sent by the master to complete the command.
During a normal write sequence, if an attempt is made
to write to a protected address, no data will be written
and the device will not report an error or abort the command. If a write command is attempted across a
secure boundary, unprotected addresses will be written
and protected addresses will not.
5.8
6.0
ACKNOWLEDGE POLLING
Since the device will not acknowledge during a write
cycle, this can be used to determine when the cycle is
complete (this feature can be used to maximize bus
throughput). Once the stop condition for a write command has been issued from the master, the device initiates the internally timed write cycle. ACK polling can
be initiated immediately. This involves the master sending a start condition followed by the control byte for a
write command (R/W = 0). If the device is still busy with
the write cycle, then no ACK will be returned. If the
cycle is complete, then the device will return the ACK
and the master can then proceed with the next read or
write command. See Figure 6-1 for flow diagram.
FIGURE 6-1:
ACKNOWLEDGE POLLING
FLOW
Send
Write Command
Send Stop
Condition to
Initiate Write Cycle
Send Start
Send Control Byte
with R/W = 0
Security Configuration Read
The status of the secure portion of memory can be read
by using the same technique as programming this
option except the READ bit (bit 6) of the configuration
byte is set to a one. After the configuration byte is sent,
the device will acknowledge and then send two bytes of
data to the master just as in a normal read sequence.
The master must acknowledge the first byte and not
acknowledge the second, and then send a stop bit to
end the sequence. The upper four bits of both of these
bytes will always be read as'1's. The lower four bits of
the first byte contains the starting secure block. The
lower four bits of the second byte contains the number
of secure blocks. The default starting secure block is fifteen and the default number of secure blocks is zero
(Figure 8-1).
DS21056H-page 8
Did Device
Acknowledge
(ACK = 0)?
No
Yes
Next
Operation
 1998 Microchip Technology Inc.
24AA65
7.0
PAGE CACHE AND ARRAY
MAPPING
The cache is a 64 byte (8 pages x 8 bytes) FIFO buffer.
The cache allows the loading of up to 64 bytes of data
before the write cycle is actually begun, effectively providing a 64-byte burst write at the maximum bus rate.
Whenever a write command is initiated, the cache
starts loading and will continue to load until a stop bit is
received to start the internal write cycle. The total
length of the write cycle will depend on how many
pages are loaded into the cache before the stop bit is
given. Maximum cycle time for each page is 5 ms. Even
if a page is only partially loaded, it will still require the
same cycle time as a full page. If more than 64 bytes of
data are loaded before the stop bit is given, the address
pointer will'wrap around' to the beginning of cache
page 0 and existing bytes in the cache will be overwritten. The device will not respond to any commands
while the write cycle is in progress.
7.1
Cache Write Starting at a Page
Boundary
If a write command begins at a page boundary
(address bits A2, A1 and A0 are zero), then all data
loaded into the cache will be written to the array in
sequential addresses. This includes writing across a
4K block boundary. In the example shown below,
(Figure 8-2) a write command is initiated starting at
byte 0 of page 3 with a fully loaded cache (64 bytes).
The first byte in the cache is written to byte 0 of page 3
(of the array), with the remaining pages in the cache
written to sequential pages in the array. A write cycle is
executed after each page is written. Since the write
begins at page 3 and 8 pages are loaded into the
cache, the last 3 pages of the cache are written to the
next row in the array.
7.2
Cache Write Starting at a Non-Page
Boundary
When a write command is initiated that does not begin
at a page boundary (i.e., address bits A2, A1 and A0
are not all zero), it is important to note how the data is
loaded into the cache, and how the data in the cache is
written to the array. When a write command begins, the
first byte loaded into the cache is always loaded into
page 0. The byte within page 0 of the cache where the
load begins is determined by the three least significant
address bits (A2, A1, A0) that were sent as part of the
write command. If the write command does not start at
byte 0 of a page and the cache is fully loaded, then the
last byte(s) loaded into the cache will roll around to
page 0 of the cache and fill the remaining empty bytes.
If more than 64 bytes of data are loaded into the cache,
data already loaded will be overwritten. In the example
shown in Figure 8-3, a write command has been initiated starting at byte 2 of page 3 in the array with a fully
loaded cache of 64 bytes. Since the cache started loading at byte 2, the last two bytes loaded into the cache
 1998 Microchip Technology Inc.
will 'roll over' and be loaded into the first two bytes of
page 0 (of the cache). When the stop bit is sent, page
0 of the cache is written to page 3 of the array. The
remaining pages in the cache are then loaded sequentially to the array. A write cycle is executed after each
page is written. If a partially loaded page in the cache
remains when the STOP bit is sent, only the bytes that
have been loaded will be written to the array.
7.3
Power Management
The design incorporates a power standby mode when
not in use and automatically powers off after the normal termination of any operation when a stop bit is
received and all internal functions are complete. This
includes any error conditions, i.e. not receiving an
acknowledge or stop condition per the two-wire bus
specification. The device also incorporates VDD monitor circuitry to prevent inadvertent writes (data corruption) during low-voltage conditions. The VDD monitor
circuitry is powered off when the device is in standby
mode in order to further reduce power consumption.
8.0
PIN DESCRIPTIONS
8.1
A0, A1, A2 Chip Address Inputs
The A0..A2 inputs are used by the 24AA65 for multiple
device operation and conform to the two-wire bus standard. The levels applied to these pins define the
address block occupied by the device in the address
map. A particular device is selected by transmitting the
corresponding bits (A2, A1, A0) in the control byte
(Figure 3-2 and Figure 8-1).
8.2
SDA Serial Address/Data Input/Output
This is a bidirectional pin used to transfer addresses
and data into and data out of the device. It is an open
drain terminal, therefore the SDA bus requires a pull-up
resistor to VCC (typical 10KΩ for 100 kHz, 2 KΩ for 400
kHz).
For normal data transfer SDA is allowed to change only
during SCL low. Changes during SCL high are
reserved for indicating the START and STOP conditions.
8.3
SCL Serial Clock
This input is used to synchronize the data transfer from
and to the device.
DS21056H-page 9
24AA65
FIGURE 8-1:
CONTROL SEQUENCE BIT ASSIGNMENTS
Control Byte
Address Byte 1
Address Byte 0
1 0 1 0 A A A R
2 1 0 W
S 0 0 A A A A A
12 11 10 9 8
A
A
7 • • • • • • 0
Configuration Byte
R X X B B B B
3 2 1 0
S/HE
Slave Device
Address Select
Bits
Block
Count
Security Read
S
t
a
r
t
Acknowledge
from
Master
Acknowledges from Device
Data from Device
R
No
ACK
S
t
Data from Device
o
p
A
A
A
A
A
1 0 1 0 A A A 0 C 1 X X X X X X X C X X X X X X X X C 1 1 X X X X X X C 1 1 1 1 B B B B C 1 1 1 1 N N N N
2 1 0
3 2 1 0
3 2 1 0 K
K
K
K
K
S/HE
Starting Block
Number
Number of
Blocks to
Protect
Security Write
S
t
a
r
t
S
t
o
p
Acknowledges from Device
R
A
A
A
A
1 0 1 0 A A A 0 C 1 X X B B B B X C X X X X X X X X C 1 0 X X N N N N C
3 2 1 0 K
2 1 0
3 2 1 0
K
K
K
S/HE
Starting Block
Number
Number of
Blocks to
Protect
High Endurance Block Read
S
t
a
r
t
Acknowledges from Device
R
No
ACK S
t
o
Data from Device
p
A
A
A
A
A
1 0 1 0 A A A 0 C 1 X X X X X X X C X X X X X X X X C 0 1 X X X X X X C 1 1 1 1 B B B B C
2 1 0
3 2 1 0 K
K
K
K
K
S/HE
High Endurance
Block Number
High Endurance Block Write
S
t
a
r
t
Acknowledges from Device
R
S
t
o
p
A
A
A
A
1 0 1 0 A A A 0 C 1 X X B B B B X C X X X X X X X X C 0 0 X X 0 0 0 0 C
2 1 0
3 2 1 0
K
K
K
K
High Endurance
Block Number
DS21056H-page 10
S/HE
 1998 Microchip Technology Inc.
24AA65
FIGURE 8-2:
CACHE WRITE TO THE ARRAY STARTING AT A PAGE BOUNDARY
1 Write command initiated at byte 0 of page 3 in the array;
First data byte is loaded into the cache byte 0.
2 64 bytes of data are loaded into cache.
cache page 0
cache
byte 0
cache
byte 1
cache
byte 7
• • •
cache page 1 cache page 2
bytes 8-15
bytes 16-23
3 Write from cache into array initiated by STOP bit.
Page 0 of cache written to page 3 of array.
Write cycle is executed after every page is written.
page 0 page 1 page 2
byte 0
byte 1
page 0 page 1 page 2
cache page 7
bytes 56-63
• • •
4 Remaining pages in cache are written
to sequential pages in array.
• • •
byte 7
page 3
page 4
• • •
page 7 array row n
page 4
• • •
page 7 array row n + 1
5 Last page in cache written to page 2 in next row.
FIGURE 8-3:
Last 2 bytes
loaded into
page 0 of cache.
CACHE WRITE TO THE ARRAY STARTING AT A NON-PAGE BOUNDARY
1 Write command initiated; 64 bytes of data
loaded into cache starting at byte 2 of page 0.
3
cache
byte 0
cache
byte 1
cache
byte 2
• • •
cache
byte 7
2 Last 2 bytes loaded 'roll over'
to beginning.
cache page 1 cache page 2
bytes 8-15
bytes 16-23
• • •
cache page 7
bytes 56-63
4 Write from cache into array initiated by STOP bit.
5 Remaining bytes in cache are
Page 0 of cache written to page 3 of array.
written sequentially to array.
Write cycle is executed after every page is written.
page 0 page 1 page 2
byte 0
byte 1
byte 2
page 0 page 1 page 2
byte 3
page 3
byte 4
• • •
byte 7
page 4
• • •
page 4
• • •
page 7 array
row n
page 7 array
row
n+1
6 Last 3 pages in cache written to next row in array.
 1998 Microchip Technology Inc.
DS21056H-page 11
24AA65
NOTES:
DS21056H-page 12
 1998 Microchip Technology Inc.
24AA65
NOTES:
 1998 Microchip Technology Inc.
DS21056H-page 13
24AA65
NOTES:
DS21056H-page 14
 1998 Microchip Technology Inc.
24AA65
24AA65 Product Identification System
To order or to obtain information, e.g., on pricing or delivery, please use the listed part numbers, and refer to the factory or the listed
sales offices.
24AA65 –
/P
Package:
Temperature
Range:
Device:
P = Plastic DIP (300 mil Body)
SM = Plastic SOIC (207 mil Body, EIAJ standard)
Blank = 0˚C to +70˚C
24AA65
24AA65T
64K I2C Serial EEPROM (100 kHz/400 kHz)
64K I2C Serial EEPROM (Tape and Reel)
Sales and Support
Data Sheets
Products supported by a preliminary Data Sheet may have an errata sheet describing minor operational differences and recommended workarounds. To determine if an errata sheet exists for a particular device, please contact one of the following:
1. Your local Microchip sales office
2. The Microchip Corporate Literature Center U.S. FAX: (602) 786-7277
3. The Microchip Worldwide Web Site (www.microchip.com)
 1998 Microchip Technology Inc.
DS21056H-page 15
WORLDWIDE SALES AND SERVICE
AMERICAS
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ASIA/PACIFIC
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ASIA/PACIFIC (continued)
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11/15/99
Microchip received QS-9000 quality system
certification for its worldwide headquarters,
design and wafer fabrication facilities in
Chandler and Tempe, Arizona in July 1999. The
Company’s quality system processes and
procedures are QS-9000 compliant for its
PICmicro® 8-bit MCUs, KEELOQ® code hopping
devices, Serial EEPROMs and microperipheral
products. In addition, Microchip’s quality
system for the design and manufacture of
development systems is ISO 9001 certified.
All rights reserved. © 1999 Microchip Technology Incorporated. Printed in the USA. 11/99
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 1999 Microchip Technology Inc.