ETC 24LC128-I/P

24AA128/24LC128/24FC128
128K I2C™CMOS Serial EEPROM
DEVICE SELECTION TABLE
PACKAGE TYPE
PDIP
Part
Number
VCC
Range
Max Clock
Frequency
24AA128
1.8-5.5V
400 kHz
C
24LC128
2.5-5.5V
400 kHz‡
I, E
24FC128
2.5-5.5V
1 MHz
I
†100
‡100
kHz for VCC < 2.5V.
kHz for E temperature range.
FEATURES
A0
1
A1
2
A2
3
Vss
4
SOIC
The Microchip Technology Inc. 24AA128/24LC128/
24FC128 (24XX128*) is a 16K x 8 (128K bit) Serial
Electrically Erasable PROM, capable of operation
across a broad voltage range (1.8V to 5.5V). It has
been developed for advanced, low power applications
such as personal communications or data acquisition.
This device also has a page-write capability of up to 64
bytes of data. This device is capable of both random
and sequential reads up to the 128K boundary. Functional address lines allow up to eight devices on the
same bus, for up to 1M bit address space. This device
is available in the standard 8-pin plastic DIP, 8-pin SOIC
(150 and 208 mil), and 14-pin TSSOP packages.
TSSOP
8
1
6
SCL
5
SDA
VCC
SDA
VSS
4
5
A0
A1
1
NC
NC
NC
A2
3
Vss
7
14
13
12
11
10
9
8
6
WP
SCL
A2
5
7
WP
3
4
Vcc
6
A1
2
8
7
2
24XX128
DESCRIPTION
A0
24XX128
• Low power CMOS technology
- Maximum write current 3 mA at 5.5V
- Maximum read current 400 µA at 5.5V
- Standby current 100 nA typical at 5.5V
• 2-wire serial interface bus, I2C compatible
• Cascadable for up to eight devices
• Self-timed ERASE/WRITE cycle
• 64-byte page-write mode available
• 5 ms max write-cycle time
• Hardware write protect for entire array
• Output slope control to eliminate ground bounce
• Schmitt trigger inputs for noise suppression
• 100,000 erase/write cycles guaranteed
• Electrostatic discharge protection > 4000V
• Data retention > 200 years
• 8-pin PDIP and SOIC (150 and 208 mil) packages
• 14-pin TSSOP package
• Temperature ranges:
- Commercial (C)
0° to +70°C
- Industrial (I):
-40°C to +85°C
- Automotive (E):
-40°C to +125°C
24XX128
†
Temp
Ranges
Vcc
WP
NC
NC
NC
SCL
SDA
BLOCK DIAGRAM
A0 A1 A2 WP
I/O
CONTROL
LOGIC
MEMORY
CONTROL
LOGIC
HV GENERATOR
XDEC
EEPROM
ARRAY
PAGE LATCHES
I/O
SCL
YDEC
SDA
VCC
VSS
SENSE AMP
R/W CONTROL
I2C is a trademark of Philips Corporation.
*24XX128 is used in this document as a generic part number for the 24AA128/24LC128/24FC128 devices.
 1999 Microchip Technology Inc.
Preliminary
DS21191F-page 1
24AA128/24LC128/24FC128
1.0
ELECTRICAL
CHARACTERISTICS
1.1
TABLE 1-1:
PIN FUNCTION TABLE
Name
Function
A0, A1, A2 User Configurable Chip Selects
Maximum Ratings*
VCC ........................................................................6.5V
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
VSS
Ground
SDA
Serial Data
SCL
Serial Clock
WP
Write Protect Input
VCC
+1.8 to 5.5V (24AA128)
+2.5 to 5.5V (24LC128)
*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:
DC CHARACTERISTICS
All parameters apply across the
specified operating ranges, unless
otherwise noted.
Commercial (C):
Industrial (I):
Automotive (E):
Parameter
Min
Max
Units
VIH
VIL
0.7 VCC
—
VHYS
0.05 VCC
—
0.3 VCC
0.2 VCC
—
V
V
V
V
VOL
—
0.40
V
ILI
-10
10
µA
ILO
CIN, COUT
-10
—
10
10
µA
pF
ICC Read
ICC Write
—
—
400
3
µA
mA
ICCS
—
1
µA
Hysteresis of Schmitt Trigger
inputs (SDA, SCL pins)
Low level output voltage
Input leakage current
Operating current
Tamb = 0°C to +70°C
Tamb = -40°C to +85°C
Tamb = -40°C to 125°C
Symbol
A0, A1, A2, SCL, SDA, and WP
pins:
High level input voltage
Low level input voltage
Output leakage current
Pin capacitance
(all inputs/outputs)
VCC = +1.8V to 5.5V
VCC = +2.5V to 5.5V
VCC = +4.5V to 5.5V
Standby current
Conditions
VCC ≥ 2.5V
VCC < 2.5V
VCC ≥ 2.5V (Note)
IOL = 3.0 mA @ VCC = 4.5V
IOL = 2.1 mA @ VCC = 2.5V
VIN = VSS or VCC, WP = VSS
VIN = VSS or VCC, WP = VCC
VOUT = VSS or VCC
VCC = 5.0V (Note)
Tamb = 25°C, fc= 1 MHz
VCC = 5.5V, SCL = 400 kHz
VCC = 5.5V
SCL = SDA = VCC = 5.5V
A0, A1, A2, WP = VSS
Note: This parameter is periodically sampled and not 100% tested.
FIGURE 1-1:
BUS TIMING DATA
THIGH
TF
SCL
SDA
OUT
WP
TR
TSU:STA
TLOW
SDA
IN
VHYS
THD:DAT
TSU:DAT
TSU:STO
THD:STA
TSP
TBUF
TAA
(protected)
TSU:WP
THD:WP
(unprotected)
DS21191F-page 2
Preliminary
 1999 Microchip Technology Inc.
24AA128/24LC128/24FC128
TABLE 1-3:
AC CHARACTERISTICS
All parameters apply across the spec- Commercial (C): VCC = +1.8V to 5.5V
ified operating ranges unless otherIndustrial (I):
VCC = +2.5V to 5.5V
wise noted.
Automotive (E): VCC = +4.5V to 5.5V
Parameter
Tamb = 0°C to +70°C
Tamb = -40°C to +85°C
Tamb = -40°C to 125°C
Symbol
Min
Max
Units
Clock frequency
FCLK
—
—
—
—
100
100
400
1000
kHz
4.5V ≤ VCC ≤ 5.5V (E Temp range)
1.8V ≤ VCC ≤ 2.5V
2.5V ≤ VCC ≤ 5.5V
24FC128 (2.5 V ≤ Vcc ≤ 5.5 V)
Clock high time
THIGH
4000
4000
600
500
—
—
—
—
ns
4.5V ≤ VCC ≤ 5.5V (E Temp range)
1.8V ≤ VCC ≤ 2.5V
2.5V ≤ VCC ≤ 5.5V
24FC128 (2.5 V ≤ Vcc ≤ 5.5 V)
Clock low time
TLOW
4700
4700
1300
500
—
—
—
—
ns
4.5V ≤ VCC ≤ 5.5V (E Temp range)
1.8V ≤ VCC ≤ 2.5V
2.5V ≤ VCC ≤ 5.5V
24FC128 (2.5 V ≤ Vcc ≤ 5.5 V)
SDA and SCL rise time
(Note 1)
TR
—
—
—
—
1000
1000
300
300
ns
4.5V ≤ VCC ≤ 5.5V (E Temp range)
1.8V ≤ VCC ≤ 2.5V
2.5V ≤ VCC ≤ 5.5V
24FC128 (2.5 V ≤ Vcc ≤ 5.5 V)
SDA and SCL fall time
(Note 1)
TF
—
—
300
100
ns
All except 24FC128
24FC128 (2.5 V ≤ Vcc ≤ 5.5 V)
START condition hold time
THD:STA
4000
4000
600
250
—
—
—
—
ns
4.5V ≤ VCC ≤ 5.5V (E Temp range)
1.8V ≤ VCC ≤ 2.5V
2.5V ≤ VCC ≤ 5.5V
24FC128 (2.5 V ≤ Vcc ≤ 5.5 V)
START condition setup time
TSU:STA
4700
4700
600
250
—
—
—
—
ns
4.5V ≤ VCC ≤ 5.5V (E Temp range)
1.8V ≤ VCC ≤ 2.5V
2.5V ≤ VCC ≤ 5.5V
24FC128 (2.5 V ≤ Vcc ≤ 5.5 V)
Data input hold time
THD:DAT
0
—
ns
(Note 2)
Data input setup time
TSU:DAT
250
250
100
100
—
—
—
—
ns
4.5V ≤ VCC ≤ 5.5V (E Temp range)
1.8V ≤ VCC ≤ 2.5V
2.5V ≤ VCC ≤ 5.5V
24FC128 (2.5 V ≤ Vcc ≤ 5.5 V)
STOP condition setup time
TSU:STO
4000
4000
600
250
—
—
—
—
ns
4.5V ≤ VCC ≤ 5.5V (E Temp range)
1.8V ≤ VCC ≤ 2.5V
2.5V ≤ VCC ≤ 5.5V
24FC128 (2.5 V ≤ Vcc ≤ 5.5 V)
WP setup time
TSU:WP
4000
4000
600
600
—
—
—
—
ns
4.5V ≤ VCC ≤ 5.5V (E Temp range)
1.8V ≤ VCC ≤ 2.5V
2.5V ≤ VCC ≤ 5.5V
24FC128 (2.5 V ≤ Vcc ≤ 5.5 V)
WP hold time
THD:WP
4700
4700
1300
1300
—
—
—
—
ns
4.5V ≤ VCC ≤ 5.5V (E Temp range)
1.8V ≤ VCC ≤ 2.5V
2.5V ≤ VCC ≤ 5.5V
24FC128 (2.5 V ≤ Vcc ≤ 5.5 V)
Note 1:
2:
3:
4:
Conditions
Not 100% tested. C B = total capacitance of one bus line in pF.
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.
The combined TSP and VHYS specifications are due to new Schmitt trigger inputs which provide improved noise spike
suppression. This eliminates the need for a TI specification for standard operation.
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 Microchip’s BBS or website.
 1999 Microchip Technology Inc.
Preliminary
DS21191F-page 3
24AA128/24LC128/24FC128
TABLE 1-3:
AC CHARACTERISTICS (CONTINUED)
All parameters apply across the spec- Commercial (C): VCC = +1.8V to 5.5V
ified operating ranges unless otherIndustrial (I):
VCC = +2.5V to 5.5V
wise noted.
Automotive (E): VCC = +4.5V to 5.5V
Parameter
Tamb = 0°C to +70°C
Tamb = -40°C to +85°C
Tamb = -40°C to 125°C
Symbol
Min
Max
Units
TAA
—
—
—
—
3500
3500
900
400
ns
4.5V ≤ VCC ≤ 5.5V (E Temp range)
1.8V ≤ VCC ≤ 2.5V
2.5V ≤ VCC ≤ 5.5V
24FC128 (2.5 V ≤ Vcc ≤ 5.5 V)
TBUF
4700
4700
1300
500
—
—
—
—
ns
4.5V ≤ VCC ≤ 5.5V (E Temp range)
1.8V ≤ VCC ≤ 2.5V
2.5V ≤ VCC ≤ 5.5V
24FC128 (2.5 V ≤ Vcc ≤ 5.5 V)
Output fall time from VIH
minimum to VIL maximum
CB ≤ 100 pF
TOF
10 + 0.1CB
250
250
ns
All except 24FC128 (Note 1)
24FC128 (Note 1)
Input filter spike suppression
(SDA and SCL pins)
TSP
—
50
ns
All except 24FC128 (Notes 1 and 3)
Write cycle time (byte or page)
TWC
—
5
ms
100K
—
cycles
Output valid from clock
(Note 2)
Bus free time: Time the bus must be
free before a new transmission can
start
Endurance
Note 1:
2:
3:
4:
Conditions
25°C, VCC = 5.0V, Block Mode (Note 4)
Not 100% tested. C B = total capacitance of one bus line in pF.
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.
The combined TSP and VHYS specifications are due to new Schmitt trigger inputs which provide improved noise spike
suppression. This eliminates the need for a TI specification for standard operation.
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 Microchip’s BBS or website.
2.0
PIN DESCRIPTIONS
2.4
2.1
A0, A1, A2 Chip Address Inputs
This pin can be connected to either VSS, VCC or left
floating. An internal pull-down resistor on this pin will
keep the device in the unprotected state if left floating.
If tied to VSS or left floating, normal memory operation
is enabled (read/write the entire memory 0000-3FFF).
The A0, A1, A2 inputs are used by the 24XX128 for
multiple device operations. The levels on these inputs
are compared with the corresponding bits in the slave
address. The chip is selected if the compare is true.
Up to eight devices may be connected to the same bus by
using different chip select bit combinations. If left unconnected, these inputs will be pulled down internally to VSS.
2.2
SDA Serial Data
This is a bi-directional pin used to transfer addresses
and data into and data out of the device. It is an opendrain terminal, therefore, the SDA bus requires a pullup
resistor to VCC (typical 10 kΩ for 100 kHz, 2 kΩ for 400
kHz and 1 MHz).
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.
2.3
WP
If tied to VCC, WRITE operations are inhibited. Read
operations are not affected.
3.0
FUNCTIONAL DESCRIPTION
The 24XX128 supports a bi-directional 2-wire bus and
data transmission protocol. A device that sends data
onto the bus is defined as a transmitter, and a device
receiving data as a 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 24XX128
works as a slave. Both master and slave can operate as
a transmitter or receiver, but the master device determines which mode is activated.
SCL Serial Clock
This input is used to synchronize the data transfer from
and to the device.
DS21191F-page 4
Preliminary
 1999 Microchip Technology Inc.
24AA128/24LC128/24FC128
4.0
BUS CHARACTERISTICS
The data on the line must be changed during the LOW
period of the clock signal. There is one bit of data per
clock pulse.
The following bus protocol has been defined:
• 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 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.
4.5
Accordingly, the following bus conditions have been
defined (Figure 4-1).
4.1
Each receiving device, when addressed, is obliged to
generate an acknowledge signal after the reception of
each byte. The master device must generate an extra
clock pulse which is associated with this acknowledge bit.
Bus not Busy (A)
Both data and clock lines remain HIGH.
4.2
Acknowledge
Note:
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.
4.3
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 (24XX128) will 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 end with a STOP condition.
4.4
The 24XX128 does not generate any
acknowledge bits if an internal programming cycle is in progress.
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.
FIGURE 4-1:
(A)
DATA TRANSFER SEQUENCE ON THE SERIAL BUS
(B)
(D)
(D)
(C)
(A)
SCL
SDA
START
CONDITION
FIGURE 4-2:
ADDRESS OR
DATA
ACKNOWLEDGE ALLOWED
VALID
TO CHANGE
STOP
CONDITION
ACKNOWLEDGE TIMING
Acknowledge
Bit
SCL
1
2
SDA
3
4
5
6
7
8
1
2
3
Data from transmitter
Data from transmitter
Transmitter must release the SDA line at this point
allowing the Receiver to pull the SDA line low to
acknowledge the previous eight bits of data.
 1999 Microchip Technology Inc.
9
Preliminary
Receiver must release the SDA line at this point
so the Transmitter can continue sending data.
DS21191F-page 5
24AA128/24LC128/24FC128
5.0
DEVICE ADDRESSING
FIGURE 5-1:
A control byte is the first byte received following the
start condition from the master device (Figure 5-1). The
control byte consists of a 4-bit control code; for the
24XX128 this is set as 1010 binary for read and write
operations. The next three bits of the control byte are
the chip select bits (A2, A1, A0). The chip select bits
allow the use of up to eight 24XX128 devices on the
same bus and are used to select which device is
accessed. The chip select bits in the control byte must
correspond to the logic levels on the corresponding A2,
A1, and A0 pins for the device to respond. 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, and when set to a zero a write operation is
selected. The next two bytes received define the
address of the first data byte (Figure 5-2). Because
only A13…A0 are used, the upper two address bits are
don’t care bits. The upper address bits are transferred
first, followed by the less significant bits.
CONTROL BYTE FORMAT
Read/Write Bit
Chip Select
Bits
Control Code
S
1
0
1
0
A2
A1
A0 R/W ACK
Slave Address
Start Bit
5.1
Acknowledge Bit
Contiguous Addressing Across
Multiple Devices
The chip select bits A2, A1, A0 can be used to expand
the contiguous address space for up to 1 Mbit by adding up to eight 24XX128's on the same bus. In this
case, software can use A0 of the control byte as
address bit A14; A1, as address bit A15; and A2, as
address bit A16. It is not possible to sequentially read
across device boundaries.
Following the start condition, the 24XX128 monitors the
SDA bus checking the device type identifier being
transmitted. Upon receiving a 1010 code and appropriate device select bits, the slave device outputs an
acknowledge signal on the SDA line. Depending on the
state of the R/W bit, the 24XX128 will select a read or
write operation.
FIGURE 5-2:
ADDRESS SEQUENCE BIT ASSIGNMENTS
CONTROL BYTE
1
0
1
CONTROL
CODE
DS21191F-page 6
0
A
2
A
1
ADDRESS HIGH BYTE
A
0 R/W
X
X
A A A A
13 12 11 10
CHIP
SELECT
BITS
A
9
ADDRESS LOW BYTE
A
8
A
7
•
•
•
•
•
•
A
0
X = Don’t Care Bit
Preliminary
 1999 Microchip Technology Inc.
24AA128/24LC128/24FC128
6.0
WRITE OPERATIONS
6.1
Byte Write
incremented by one. If the master should transmit more
than 64 bytes prior to generating the stop condition, the
address counter will roll over and the previously
received data will be overwritten. As with the byte write
operation, once the stop condition is received, an internal write cycle will begin (Figure 6-2). If an attempt is
made to write to the array with the WP pin held high, the
device will acknowledge the command but no write
cycle will occur, no data will be written, and the device
will immediately accept a new command.
Following the start condition from the master, the
control code (four bits), the chip select (three bits), and
the R/W bit (which is a logic low) are clocked onto the
bus by the master transmitter. This indicates to the
addressed slave receiver that the address high byte will
follow after it has generated an acknowledge bit during
the ninth clock cycle. Therefore, the next byte
transmitted by the master is the high-order byte of the
word address and will be written into the address
pointer of the 24XX128. The next byte is the least significant address byte. After receiving another acknowledge signal from the 24XX128, the master device will
transmit the data word to be written into the addressed
memory location. The 24XX128 acknowledges again
and the master generates a stop condition. This initiates the internal write cycle, and, during this time, the
24XX128 will not generate acknowledge signals
(Figure 6-1). If an attempt is made to write to the array
with the WP pin held high, the device will acknowledge
the command but no write cycle will occur, no data will
be written, and the device will immediately accept a
new command. After a byte write command, the internal address counter will point to the address location
following the one that was just written.
6.2
6.3
Write Protection
The WP pin allows the user to write-protect the entire
array (0000-3FFF) when the pin is tied to VCC. If tied to
VSS or left floating, the write protection is disabled. The
WP pin is sampled at the STOP bit for every write
command (Figure 1-1) Toggling the WP pin after the
STOP bit will have no effect on the execution of the
write cycle.
Note:
Page write operations are limited to writing
bytes within a single physical page, regardless of the number of bytes actually being
written. Physical page boundaries start at
addresses that are integer multiples of the
page buffer size (or ‘page size’) and end at
addresses that are integer multiples of
[page size - 1]. If a page write command
attempts to write across a physical page
boundary, the result is that the data wraps
around to the beginning of the current page
(overwriting data previously stored there),
instead of being written to the next page as
might be expected. It is therefore necessary for the application software to prevent
page write operations that would attempt to
cross a page boundary.
Page Write
The write control byte, word address, and the first data
byte are transmitted to the 24XX128 in the same way
as in a byte write. But instead of generating a stop condition, the master transmits up to 63 additional bytes,
which are temporarily stored in the on-chip page buffer
and will be written into memory after the master has
transmitted a stop condition. After receipt of each word,
the six lower address pointer bits are internally
FIGURE 6-1:
BYTE WRITE
S
T
A
R
T
BUS ACTIVITY
MASTER
CONTROL
BYTE
ADDRESS
HIGH BYTE
A A
S 1 0 1 0 A
2 1 0 0
SDA LINE
S
T
O
P
DATA
X X
P
A
C
K
BUS ACTIVITY
ADDRESS
LOW BYTE
A
C
K
A
C
K
A
C
K
X = don’t care bit
FIGURE 6-2:
PAGE WRITE
BUS ACTIVITY
MASTER
S
T
A
R
T
SDA LINE
S10 1 0 2 1 0 0
CONTROL
BYTE
ADDRESS
HIGH BYTE
A A A
BUS ACTIVITY
ADDRESS
LOW BYTE
DATA BYTE 0
S
T
O
P
DATA BYTE 63
XX
A
C
K
P
A
C
K
A
C
K
A
C
K
A
C
K
X = don’t care bit
 1999 Microchip Technology Inc.
Preliminary
DS21191F-page 7
24AA128/24LC128/24FC128
7.0
ACKNOWLEDGE POLLING
FIGURE 7-1:
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 no
ACK is returned, then the start bit and control byte must
be resent. 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 7-1 for
flow diagram.
ACKNOWLEDGE POLLING
FLOW
Send
Write Command
Send Stop
Condition to
Initiate Write Cycle
Send Start
Send Control Byte
with R/W = 0
Did Device
Acknowledge
(ACK = 0)?
NO
YES
Next
Operation
DS21191F-page 8
Preliminary
 1999 Microchip Technology Inc.
24AA128/24LC128/24FC128
8.0
READ OPERATION
8.2
Read operations are initiated in the same way as write
operations with the exception that the R/W bit of the
control byte is set to one. There are three basic types
of read operations: current address read, random read,
and sequential read.
8.1
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
24XX128 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
24XX128 will then issue an acknowledge and transmit
the 8-bit data word. The master will not acknowledge
the transfer but does generate a stop condition which
causes the 24XX128 to discontinue transmission
(Figure 8-2). After a random read command, the internal address counter will point to the address location
following the one that was just read.
Current Address Read
The 24XX128 contains an address counter that maintains the address of the last word accessed, internally
incremented by one. Therefore, if the previous read
access 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 control byte with R/W bit set to one,
the 24XX128 issues an acknowledge and transmits the
8-bit data word. The master will not acknowledge the
transfer but does generate a stop condition and the
24XX128 discontinues transmission (Figure 8-1).
FIGURE 8-1:
8.3
S
T
A
R
T
SDA LINE
S 1 0 1 0 A AA 1
2 1 0
P
A
C
K
BUS ACTIVITY
FIGURE 8-2:
S
T
O
P
DATA
BYTE
CONTROL
BYTE
Sequential Read
Sequential reads are initiated in the same way as a random read except that after the 24XX128 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 24XX128 to transmit the
next sequentially addressed 8-bit word (Figure 8-3).
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
24XX128 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. The
internal address pointer will automatically roll over from
address 3FFF to address 0000 if the master acknowledges the byte received from the array address 3FFF.
CURRENT ADDRESS READ
BUS ACTIVITY
MASTER
Random Read
N
O
A
C
K
RANDOM READ
S
T
A
R
T
BUS ACTIVITY
MASTER
CONTROL
BYTE
ADDRESS
HIGH BYTE
S1 0 1 0 AAA0
2 1 0
SDA LINE
ADDRESS
LOW BYTE
CONTROL
BYTE
S
T
O
P
DATA
BYTE
S 1 0 1 0 A A A1
2 1 0
XX
A
C
K
BUS ACTIVITY
S
T
A
R
T
A
C
K
A
C
K
DATA n + 1
DATA n + 2
P
N
O
A
C
K
A
C
K
X = Don’t Care Bit
FIGURE 8-3:
SEQUENTIAL READ
BUS ACTIVITY
MASTER
CONTROL
BYTE
DATA n
P
SDA LINE
BUS ACTIVITY
 1999 Microchip Technology Inc.
S
T
O
P
DATA n + X
A
C
K
A
C
K
Preliminary
A
C
K
A
C
K
N
O
A
C
K
DS21191F-page 9
24AA128/24LC128/24FC128
NOTES:
DS21191F-page 10
Preliminary
 1999 Microchip Technology Inc.
24AA128/24LC128/24FC128
24XX128 PRODUCT IDENTIFICATION SYSTEM
To order or obtain information, e.g., on pricing or delivery, refer to the factory or the listed sales office.
24XX128
—
/P
Package:
Temperature
Range:
Device:
P
SN
ST
OT
=
=
=
=
Plastic DIP (300 mil Body), 8-lead
Plastic SOIC (150 mil Body)
TSSOP, 8-lead
SOT-23, 5-lead
Blank = 0°C to +70°C
I = –40°C to +85°C
E = –40°C to +125°C
24AA128
24AA128T
24LC128
24LC128T
24FC128
24FC128T
128 bit 1.8V I2C Serial EEPROM
128 bit 1.8V K I2C Serial EEPROM (Tape and Reel)
128 bit 2.5V I2C Serial EEPROM
128 bit 2.5V K I2C Serial EEPROM (Tape and Reel)
128 bit 1MHz I2C Serial EEPROM
128 bit 1MHz 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.
2.
3.
Your local Microchip sales office
The Microchip Corporate Literature Center U.S. FAX: (602) 786-7277. After September 1, 1999, (480) 786-7277
The Microchip Worldwide Site (www.microchip.com)
Please specify which device, revision of silicon and Data Sheet (include Literature #) you are using.
New Customer Notification System
Register on our web site (www.microchip.com/cn) to receive the most current information on our products.
 1999 Microchip Technology Inc.
Preliminary
DS21191F-page 11
WORLDWIDE SALES AND SERVICE
AMERICAS
AMERICAS (continued)
Corporate Office
Toronto
Singapore
Microchip Technology Inc.
2355 West Chandler Blvd.
Chandler, AZ 85224-6199
Tel: 480-786-7200 Fax: 480-786-7277
Technical Support: 480-786-7627
Web Address: http://www.microchip.com
Microchip Technology Inc.
5925 Airport Road, Suite 200
Mississauga, Ontario L4V 1W1, Canada
Tel: 905-405-6279 Fax: 905-405-6253
Microchip Technology Singapore Pte Ltd.
200 Middle Road
#07-02 Prime Centre
Singapore 188980
Tel: 65-334-8870 Fax: 65-334-8850
Atlanta
Microchip Asia Pacific
Unit 2101, Tower 2
Metroplaza
223 Hing Fong Road
Kwai Fong, N.T., Hong Kong
Tel: 852-2-401-1200 Fax: 852-2-401-3431
Microchip Technology Inc.
500 Sugar Mill Road, Suite 200B
Atlanta, GA 30350
Tel: 770-640-0034 Fax: 770-640-0307
Boston
Microchip Technology Inc.
5 Mount Royal Avenue
Marlborough, MA 01752
Tel: 508-480-9990 Fax: 508-480-8575
Chicago
Microchip Technology Inc.
333 Pierce Road, Suite 180
Itasca, IL 60143
Tel: 630-285-0071 Fax: 630-285-0075
Dallas
Microchip Technology Inc.
4570 Westgrove Drive, Suite 160
Addison, TX 75248
Tel: 972-818-7423 Fax: 972-818-2924
Dayton
Microchip Technology Inc.
Two Prestige Place, Suite 150
Miamisburg, OH 45342
Tel: 937-291-1654 Fax: 937-291-9175
Detroit
Microchip Technology Inc.
Tri-Atria Office Building
32255 Northwestern Highway, Suite 190
Farmington Hills, MI 48334
Tel: 248-538-2250 Fax: 248-538-2260
Los Angeles
Microchip Technology Inc.
18201 Von Karman, Suite 1090
Irvine, CA 92612
Tel: 949-263-1888 Fax: 949-263-1338
New York
Microchip Technology Inc.
150 Motor Parkway, Suite 202
Hauppauge, NY 11788
Tel: 631-273-5305 Fax: 631-273-5335
San Jose
Microchip Technology Inc.
2107 North First Street, Suite 590
San Jose, CA 95131
Tel: 408-436-7950 Fax: 408-436-7955
ASIA/PACIFIC
Hong Kong
ASIA/PACIFIC (continued)
Taiwan, R.O.C
Microchip Technology Taiwan
10F-1C 207
Tung Hua North Road
Taipei, Taiwan, ROC
Tel: 886-2-2717-7175 Fax: 886-2-2545-0139
EUROPE
Beijing
United Kingdom
Microchip Technology, Beijing
Unit 915, 6 Chaoyangmen Bei Dajie
Dong Erhuan Road, Dongcheng District
New China Hong Kong Manhattan Building
Beijing 100027 PRC
Tel: 86-10-85282100 Fax: 86-10-85282104
Arizona Microchip Technology Ltd.
505 Eskdale Road
Winnersh Triangle
Wokingham
Berkshire, England RG41 5TU
Tel: 44 118 921 5858 Fax: 44-118 921-5835
India
Denmark
Microchip Technology Inc.
India Liaison Office
No. 6, Legacy, Convent Road
Bangalore 560 025, India
Tel: 91-80-229-0061 Fax: 91-80-229-0062
Microchip Technology Denmark ApS
Regus Business Centre
Lautrup hoj 1-3
Ballerup DK-2750 Denmark
Tel: 45 4420 9895 Fax: 45 4420 9910
Japan
France
Microchip Technology Intl. Inc.
Benex S-1 6F
3-18-20, Shinyokohama
Kohoku-Ku, Yokohama-shi
Kanagawa 222-0033 Japan
Tel: 81-45-471- 6166 Fax: 81-45-471-6122
Arizona Microchip Technology SARL
Parc d’Activite du Moulin de Massy
43 Rue du Saule Trapu
Batiment A - ler Etage
91300 Massy, France
Tel: 33-1-69-53-63-20 Fax: 33-1-69-30-90-79
Korea
Germany
Microchip Technology Korea
168-1, Youngbo Bldg. 3 Floor
Samsung-Dong, Kangnam-Ku
Seoul, Korea
Tel: 82-2-554-7200 Fax: 82-2-558-5934
Arizona Microchip Technology GmbH
Gustav-Heinemann-Ring 125
D-81739 München, Germany
Tel: 49-89-627-144 0 Fax: 49-89-627-144-44
Shanghai
Arizona Microchip Technology SRL
Centro Direzionale Colleoni
Palazzo Taurus 1 V. Le Colleoni 1
20041 Agrate Brianza
Milan, Italy
Tel: 39-039-65791-1 Fax: 39-039-6899883
Microchip Technology
RM 406 Shanghai Golden Bridge Bldg.
2077 Yan’an Road West, Hong Qiao District
Shanghai, PRC 200335
Tel: 86-21-6275-5700 Fax: 86 21-6275-5060
Italy
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
Printed on recycled paper.
Information contained in this publication regarding device applications and the like is intended for suggestion only and may be superseded by updates. No representation or warranty is given and no liability is assumed
by Microchip Technology Incorporated with respect to the accuracy or use of such information, or infringement of patents or other intellectual property rights arising from such use or otherwise. Use of Microchip’s products
as critical components in life support systems is not authorized except with express written approval by Microchip. No licenses are conveyed, implicitly or otherwise, under any intellectual property rights. The Microchip
logo and name are registered trademarks of Microchip Technology Inc. in the U.S.A. and other countries. All rights reserved. All other trademarks mentioned herein are the property of their respective companies.
 1999 Microchip Technology Inc.