• Organized as a single block of 256 b ytes (256 x 8)
• Hardware write protection for upper half of array
• 2-wire serial interface bus, I
• 100 kHz and 400 kHz compatibility
• Page-write buffer for up to 16 bytes
• Self-timed write cycle (including auto-erase)
• Fast 1 mS write cycle time for byte or page mode
• Address lines allow up to eight devices on bus
• 1,000,000 erase/write cycles guaranteed
• ESD protection > 4,000V
• Data retention > 200 years
• 8-pin PDIP, SOIC or TSSOP packages
• Available for extended temperature ranges
- Commercial (C):0 ° C to+70 ° C
- Industrial (I): -40 ° C to+85 ° C
- Automotive (E): -40 ° C to +125 ° C
2
C compatible
2
C
™
Serial EEPROM
PACKA GE TYPES
PDIP/SOIC
A0
A1
A2
Vss
TSSOP
A0
A1
A2
V
SS
24C02C
Vcc
24C02C
8
WP
7
SCL
6
SDA
5
8
VCC
7
WP
6
SCL
5
SDA
1
24C02C
2
3
4
1
2
3
4
DESCRIPTION
The Microchip Technology Inc. 24C02C is a 2K bit
Serial Electrically Erasable PROM with a voltage range
of 4.5V to 5.5V. The device is organized as a single
block of 256 x 8-bit memory with a 2-wire serial interface. Low current design permits operation with typical
standby and active currents of only 10 µ A and 1 mA
respectively. The device has a page-write capability for
up to 16 bytes of data and has fast write cycle times of
only 1 mS for both byte and page writes. Functional
address lines allow the connection of up to eight
24C02C devices on the same bus for up to 16K bits of
contiguous EEPROM memory. The device is available
in the standard 8-pin PDIP, 8-pin SOIC (150 mil), and
TSSOP packages.
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:DC CHARACTERISTICS
All parameters apply across the specified operating ranges unless otherwise
noted.
SCL and SDA pins:
High level input voltageV
Low level input voltageV
Hysteresis of Schmitt trigger inputsV
Note : This parameter is periodically sampled and not 100% tested.
um Ratings*
......-0.6V to V
SS
ParameterSymbolMin.Max.UnitsConditions
+1.0V
CC
V
= +4.5V to +5.5V
CC
Commercial (C):Tamb = 0 ° C to +70 ° C
Industrial (I):Tamb = -40 ° C to +85 ° C
Automotive (E):Tamb = -40 ° C to +125 ° C
IH
IL
HYS
OL
LI
LO
IN
OUT
C
, C
I
CC
Read—1mAV
Write—3mAV
CC
I
CCS
CC
0.7 V
—0.3 V
CC
0.05 V
—0.40VI
-1010
-1010
—10pFV
—50
TABLE 1-1:PIN FUNCTION TABLE
NameFunction
V
SS
SDA
SCL
CC
V
A0, A1, A2
WP
—V
CC
—V(Note)
Ground
Serial Data
Serial Clock
+4.5V to 5.5V Power Supply
Chip Selects
Hardware Write Protect
V
= 3.0 mA, Vcc = 4.5V
OL
IN
AV
AV
= 0.1V to 5.5V, WP = Vss
= 0.1V to 5.5V
OUT
CC
= 5.0V (Note)
Tamb = 25 ° C, f = 1 MHz
CC
= 5.5V, SCL = 400 kHz
= 5.5V
CC
CC
AV
= 5.5V, SDA = SCL = V
CC
DS21202A-page 2
Preliminary
1997 Microchip Technology Inc.
24C02C
TABLE 1-3:AC CHARACTERISTICS
All parameters apply across the specified operating ranges unless otherwise noted.
Tamb > +85 ° C -40 ° C
ParameterSymbol
Min.Max.Min.Max.
Clock frequencyF
Clock high timeT
Clock low timeT
SDA and SCL rise timeT
SDA and SCL fall timeT
START condition hold timeT
START condition setup timeT
Data input hold timeT
Data input setup timeT
STOP condition setup timeT
Output valid from clockT
Bus free timeT
Output fall time from V
minimum to V
IL
IH
maximum
Input filter spike suppression
HIGH
LOW
HD
SU
HD
SU
SU
T
T
CLK
R
F
:
STA
STA
:
:
DAT
DAT
:
:
STO
AA
BUF
OF
SP
4000—600—ns
4700—1300—ns
4000—600—nsAfter this period the first
4700—600—nsOnly relevant for repeated
4000—600—ns
4700—1300—nsTime the bus must be free
(SDA and SCL pins)
Write cycle timeT
WR
Endurance1M—1M—cycles 25 ° C, V
Note 1: Not 100% tested. C
= total capacitance of one bus line in pF.
B
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 T
SP and VHYS specifications are due to Schmitt trigger inputs which provide improved noise
spike suppression. This eliminates the need for a TI specification for standard operation.
4: This parameter is not tested but guaranteed by characterization. For endurance estimates in a specific appli-
cation, please consult the Total Endurance Model which can be obtained on our BBS or website.
Vcc = 4.5V to 5.5V
Commercial (C):Tamb = 0 ° C to +70 ° C
Industrial (I):Tamb = -40 ° C to +85 ° C
Automotive (E):Tamb = -40 ° C to +125 ° C
≤
Tamb
≤
+85 ° C
UnitsRemarks
—100—400kHz
—1000—300ns(Note 1)
—300—300ns(Note 1)
clock pulse is generated
START condition
0—0—ns(Note 2)
250—100—ns
—3500—900ns(Note 2)
before a new transmission
can start
—25020 + 0.1 C
250ns(Note 1), C
B
B
—50—50ns(Note 3)
—1.5—1msByte or Page mode
CC
= 5.0V, Block
Mode (Note 4)
100 pF
≤
2:
3:
FIGURE 1-1:BUS TIMING DATA
TF
SCL
SDA
IN
SDA
OUT
1997 Microchip Technology Inc.
TSU:STA
TSP
TLOW
THD:STA
THIGH
THD:DATTSU:DATTSU:STO
TAA
TR
Preliminary
TBUF
DS21202A-page 3
24C02C
2.0PIN DESCRIPTIONS
2.1SDA Serial Data
This is a bi-directional 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 V
400 kHz).
For normal data transfer SD A is allow ed to change only
during SCL low. Changes during SCL high are reserved
for indicating the START and STOP conditions.
2.2SCL Serial Clock
This input is used to synchronize the data transfer from
and to the device.
2.3A0, A1, A2
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 24C02C devices may be connected to the
same bus by using different chip select bit combinations. These inputs must be connected to either V
V
SS.
CC (typical 10 kΩ for 100 kHz, 2 kΩ for
CC or
3.0FUNCTIONAL DESCRIPTION
The 24C02C supports a bi-directional 2-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 has to 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 24C02C works
as slave. Both master and slave can operate as transmitter or receiver but the master device determines
which mode is activated.
2.4WP
This is the hardware write protect pin. It must be tied to
V
CC or VSS. If tied to Vcc, the hardware write protection
is enabled. If the WP pin is tied to Vss the hardware
write protection is disabled.
2.5Noise Protection
The 24C02C employs a VCC threshold detector circuit
which disables the internal erase/write logic if the V
is below 3.8 volts at nominal conditions.
The SCL and SDA inputs hav e Schmitt trigger and filter
circuits which suppress noise spikes to assure proper
device operation even on a noisy bus.
CC
DS21202A-page 4Preliminary 1997 Microchip Technology Inc.
24C02C
4.0BUS CHARACTERISTICS
The following bus protocol has been defined:
• Data transfer may be initiated only when the b us 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.
Accordingly, the following bus conditions have been
defined (Figure 4-1).
4.1Bus not Busy (A)
Both data and clock lines remain HIGH.
4.2Start 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.
4.3Stop 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.
4.4Data 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 bit of data per
clock pulse.
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
and is theoretically unlimited, although only the last sixteen will be stored when doing a write operation. When
an overwrite does occur it will replace data in a first in
first out fashion.
4.5Acknowledge
Each receiving device, when addressed, is required 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.
Note:The 24C02C does not generate any
acknowledge bits if an internal programming cycle is in progress.
The device that acknowledges has to pull down the
SDA line during the acknowledge cloc k 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. 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 sla ve. In this case,
the slave must leave the data line HIGH to enable the
master to generate the STOP condition (Figure 4-2).
FIGURE 4-1:DATA TRANSFER SEQUENCE ON THE SERIAL BUS CHARACTERISTICS
(A)(B)(C)(D)(A)(C)
SCL
SDA
START
CONDITION
ADDRESS OR
ACKNOWLEDGE
VALID
DATA
ALLOWED
TO CHANGE
FIGURE 4-2:ACKNOWLEDGE TIMING
Acknowledge
Bit
SCL
SDA
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.
987654321123
Data from transmitter
Receiver must release the SDA line at this point
so the Transmitter can continue sending data.
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 four bit control code; for the
24C02C 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 24C02C 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. Following the start condition, the 24C02C
monitors the SDA bus checking the control byte being
transmitted. Upon receiving a 1010 code and appropriate chip select bits, the slave device outputs an
acknowledge signal on the SD A line. Depending on the
state of the R/W
write operation.
bit, the 24C02C will select a read or
FIGURE 5-1:CONTROL BYTE FORMAT
Control Code
1010A2 A1 A0SACKR/W
Slave Address
Start Bit
5.1Contiguous Ad
Read/Wr
Chip Select
dressing Across
ite Bit
Bits
Acknowledge Bit
Multiple Devices
The chip select bits A2, A1, A0 can be used to expand
the contiguous address space for up to 16K bits by adding up to eight 24C02C devices on the same bus. In this
case, software can use A0 of the control b
address bit A8, A1 as address bit A9, and A2 as
address bit A10. It is not possib le to write or read across
device boundaries.
yte as
DS21202A-page 6Preliminary 1997 Microchip Technology Inc.
24C02C
6.0WRITE OPERATIONS
6.1Byte Write
Following the start signal from the master, the device
code (4 bits), the chip select bits (3 bits), and the R/W
bit which is a logic low is placed onto the bus by the
master transmitter. The device will acknowledge this
control byte during the ninth clock pulse. The next byte
transmitted by the master is the word address and will
be written into the address pointer of the 24C02C. After
receiving another acknowledge signal from the
24C02C the master device will transmit the data word
to be written into the addressed memory location. The
24C02C acknowledges again and the master generates a stop condition. This initiates the internal write
cycle, and during this time the 24C02C will not generate
acknowledge signals (Figure 6-1). If an attempt is made
to write to the protected portion of the array when the
hardware write protection has been enabled, the device
will acknowledge the command but no data will be written. The write cycle time must be observed even if the
write protection is enabled.
6.2Page Write
The write control byte, word address and the first data
byte are transmitted to the 24C02C in the same wa y as
in a byte write. But instead of generating a stop condition, the master transmits up to 15 additional data bytes
to the 24C02C which are temporarily stored in the onchip page buffer and will be written into the memory
after the master has transmitted a stop condition. After
the receipt of each word, the four lower order address
pointer bits are internally incremented by one. The
higher order four bits of the word address remains constant. If the master should transmit more than 16 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 protected portion of the array when the
hardware write protection has been enabled, the device
will acknowledge the command but no data will be written. The write cycle time must be observed even if the
write protection is enabled.
6.3WRITE PROTECTION
The WP pin must be tied to VCC or VSS. If tied to VCC,
the upper half of the array (080-0FF) will be write protected. If the WP pin is tied to V
to all address locations are allowed.
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 in v olv es the master sending a start condition followed by the control byte for a
write command (R/W
the write cycle, then no ACK will be returned. If no ACK
is returned, then the start bit and control byte must be
re-sent. 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.
= 0). If the de vice is still b usy with
FIGURE 7-1: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)?
YES
NO
Next
Operation
DS21202A-page 8Preliminary 1997 Microchip Technology Inc.
24C02C
8.0READ OPERATIONS
Read operations are initiated in the same way as write
operations with the exception that the R/W
slave address is set to one. There are three basic types
of read operations: current address read, random read,
and sequential read.
8.1Current Address Read
The 24C02C 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, the next current address read
operation would access data from address n + 1. Upon
receipt of the slave address with the R/W
the 24C02C 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
24C02C discontinues transmission (Figure 8-1).
8.2Random 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
24C02C as part of a write operation. After the word
bit of the
bit set to one,
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 24C02C will then
issue an acknowledge and transmits the eight bit data
word. The master will not acknowledge the transfer but
does generate a stop condition and the 24C02C discontinues transmission (Figure 8-2). After this command, the internal address counter will point to the
address location following the one that was just read.
8.3Sequential Read
Sequential reads are initiated in the same way as a random read except that after the 24C02C transmits the
first data byte, the master issues an acknowledge as
opposed to a stop condition in a random read. This
directs the 24C02C to transmit the next sequentially
addressed 8-bit word (Figure 8-3).
To provide sequential reads the 24C02C 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 FF to address 00.
DS21202A-page 10Preliminary 1997 Microchip Technology Inc.
24C02C
24C02C PRODUCT IDENTIFICATION SYSTEM
To order or obtain information, e.g., on pricing or delivery, refer to the factory or the listed sales office.
24C02C —/P
Package:
Temperature
Range:
Device:
24C02CT2K I
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 (see last page).
2.The Microchip Corporate Literature Center U.S. FAX: (602) 786-7277.
3.The Microchip’s Bulletin Board, via your local CompuServe number (CompuServe membership NOT required).
Please specify which device, revision of silicon and Data Sheet (include Literature #) you are using.
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.
DS21202A-page 12
Preliminary
1997 Microchip Technology Inc.
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