C Bus

Purchase of Siemens

C components conveys the license under the Philips

C patent to use the components in

the

C system provided the system conforms to the

C specifications defined by Philips.

Edition 1998-07-27

Published by Siemens AG,
Bereich Halbleiter, Marketing-
Kommunikation, Balanstraße 73,
81541 München

Siemens AG 1998.

As far as patents or other rights of third parties are concerned, liability is only assumed for components, not for applications, processes
and circuits implemented within components or assemblies.
The information describes the type of component and shall not be considered as assured characteristics.

Terms of delivery and rights to change design reserved.
For questions on technology, delivery and prices please contact the Semiconductor Group Offices in Germany or the Siemens Companies
and Representatives worldwide (see address list).
Due to technical requirements components may contain dangerous substances. For information on the types in question please contact
your nearest Siemens Office, Semiconductor Group.

Siemens AG is an approved CECC manufacturer.
Packing
Please use the recycling operators known to you. We can also help you get in touch with your nearest sales office. By agreement we
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For packing material that is returned to us unsorted or which we are not obliged to accept, we shall have to invoice you for any costs in-
curred.
Components used in life-support devices or systems must be expressly authorized for such purpose!
Critical components

of the Semiconductor Group of Siemens AG, may only be used in life-support devices or systems

with the express

written approval of the Semiconductor Group of Siemens AG.
1 A critical component is a component used in a life-support device or system whose failure can reasonably be expected to cause the

failure of that life-support device or system, or to affect its safety or effectiveness of that device or system.

2 Life support devices or systems are intended (a) to be implanted in the human body, or (b) to support and/or maintain and sustain hu-

man life. If they fail, it is reasonable to assume that the health of the user may be endangered.

SLx 24C08/16
Revision History:

Current Version: 1998-07-27

Previous Version:

06.97

Page
(in previous
Version)

Page
(in current
Version)

Subjects (major changes since last revision)

Text was changed to "Typical programming time 5 ms for up to
16 bytes".

WP =

protects upper half entire memory.

4, 5

CS0, CS1 and CS2 were replaced by n.c.

The paragraph "Chip Select (CS0, CS1, CS2)" was removed
completely.

11, 12

The erase/write cycle is finished latest after 10 8 ms.

Figure 11: second command byte is a CSR and not CSW.

"Capacitive load ..." were added.

Some timings were changed.

The line "erase/write cycle" was removed.

Chapter 7.4 "Erase and Write Characteristics" has been added.

P-DIP-8-4

P-DSO-8-3

8/16 Kbit (1024/2048

8 bit) Serial CMOS

EEPROMs,

C Synchronous 2-Wire Bus

SLx 24C08/16

Semiconductor Group

1998-07-27

Features

· Data EEPROM internally organized as

1024/2048 bytes and 64/128 pages

16 bytes

· Low power CMOS

= 2.7 to 5.5 V operation

· Two wire serial interface bus,

C-Bus

compatible

· Filtered inputs for noise suppression with

Schmitt trigger

· Clock frequency up to 400 kHz

· High programming flexibility

Internal programming voltage
Self timed programming cycle including erase
Byte-write and page-write programming, between

1 and 16 bytes

Typical programming time 5 ms for up to 16 bytes

· High reliability

Endurance 10

cycles

Data retention 40 years

ESD protection 4000 V on all pins

· 8 pin DIP/DSO packages

· Available for extended temperature ranges

Industrial:

40 °C to + 85 °C

Automotive:

40 °C to + 125 °C

Values are temperature dependent, for further information please refer to your Siemens Sales office.

SLx 24C08/16

Semiconductor Group

1998-07-27

Ordering Information

Other types are available on request

Temperature range (

55 °C

...

+ 150 °C)

Package (die, wafer delivery)

Pin Configuration

Figure 1
Pin Configuration (top view)

Type

Ordering Code

Package

Temperature

Voltage

SLA 24C08-D

Q67100-H3572

P-DIP-8-4

40 °C ... + 85 °C

4.5 V...5.5 V

SLA 24C08-S

Q67100-H3518

P-DSO-8-3

40 °C ... + 85 °C

4.5 V...5.5 V

SLA 24C08-D-3

Q67100-H3435

P-DIP-8-4

40 °C ... + 85 °C

2.7 V...5.5 V

SLA 24C08-S-3

Q67100-H3517

P-DSO-8-3

40 °C ... + 85 °C

2.7 V...5.5 V

SLE 24C08-D

Q67100-H3226

P-DIP-8-4

40°C ... + 125 °C 4.5 V...5.5 V

SLE 24C08-S

Q67100-H3227

P-DSO-8-3

40°C ... + 125 °C 4.5 V...5.5 V

SLA 24C16-D

Q67100-H3513

P-DIP-8-4

40 °C ... + 85 °C

4.5 V...5.5 V

SLA 24C16-S

Q67100-H3508

P-DSO-8-3

40 °C ... + 85 °C

4.5 V...5.5 V

SLA 24C16-D-3

Q67100-H3512

P-DIP-8-4

40 °C ... + 85 °C

2.7 V...5.5 V

SLA 24C16-S-3

Q67100-H3507

P-DSO-8-3

40 °C ... + 85 °C

2.7 V...5.5 V

SLE 24C16-D

Q67100-H3229

P-DIP-8-4

40°C ... + 125 °C 4.5 V...5.5 V

SLE 24C16-S

Q67100-H3230

P-DSO-8-3

40°C ... + 125 °C 4.5 V...5.5 V

P-DSO-8-3

P-DIP-8-4

IEP02514

N.C.

WP
SCL
SDA

N.C.
N.C.

IEP02515

SCL

SDA

N.C.

SLx 24C08/16

Semiconductor Group

1998-07-27

Pin Definitions and Functions

Pin Description

Serial Clock (SCL)

The SCL input is used to clock data into the device on the rising edge and to clock data
out of the device on the falling edge.

Serial Data (SDA)

SDA is a bidirectional pin used to transfer addresses, data or control information into the
device or to transfer data out of the device. The output is open drain, performing a wired
AND function with any number of other open drain or open collector devices. The SDA
bus requires a pull-up resistor to

Write Protection (WP)

WP switched to

allows normal read/write operations.

WP switched to

protects the entire EEPROM against changes (hardware write

protection).

Table 1

Pin No.

Symbol

Function

1, 2, 3

N. C.

Not connected

Ground

SDA

Serial bidirectional data bus

SCL

Serial clock input

Write protection input

Supply voltage

SLx 24C08/16

Semiconductor Group

1998-07-27

Description

The SLx 24C08/16 device is a serial electrically erasable and programmable read only
memory (EEPROM), organized as 1024/2048

8 bit. The data memory is divided into

64/128 pages. The 16 bytes of a page can be programmed simultaneously.

The device conforms to the specification of the 2-wire serial

C-Bus. Low voltage design

permits operation down to 2.7 V with low active and standby currents.

The device operates at 5.0 V

10% with a maximum clock frequency of 400 kHz and at

2.7 ... 4.5 V with a maximum clock frequency of 100 kHz. The device is available as 5 V
type (

= 4.5 ... 5.5 V) with two temperature ranges for industrial and automotive

applications and as 3 V type (

= 2.7 ... 5.5 V) for industrial applications. The

EEPROMs are mounted in eight-pin DIP and DSO packages or are also supplied as
chips.

Figure 2
Block Diagram

DEC

EEPROM

Y DEC

Dout/ACK

SDA

SCL

IEB02530

Logic

Stop

Start/

Control

Chip Address

Logic

H.V. Pump

Programming

Control

Serial

Logic

Address

Page Logic

SLx 24C08/16

Semiconductor Group

1998-07-27

C-Bus Characteristics

The SLx 24C08/16 devices support a master/slave bidirectional bus oriented protocol in
which the EEPROM always takes the role of a slave.

Figure 3
Bus Configuration

Master

Device that initiates the transfer of data and provides the clock for both
transmit and receive operations.

Slave

Device addressed by the master, capable of receiving and transmitting
data.

Transmitter The device with the SDA as output is defined as the transmitter. Due to

the open drain characteristic of the SDA output the device applying a low
level wins.

Receiver

The device with the SDA as input is defined as the receiver.

Slave 1

Slave 2

Slave 3

Slave 4

Slave 8

Slave 5

Slave 6

Slave 7

Master

IES02183

SCL

SDA

SLx 24C08/16

Semiconductor Group

1998-07-27

The conventions for the serial clock line and the bidirectional data line are shown in
figure 4.

Figure 4

C-Bus Timing Conventions for START Condition, STOP Condition, Data Valida-

tion and Transfer of Acknowledge ACK

Standby

Mode in which the bus is not busy (no serial transmission, no
programming): both clock (SCL) and data line (SDA) are in high
state. The device enters the standby mode after a STOP condition
or after a programming cycle.

START Condition

High to low transition of SDA when SCL is high, preceding all
commands.

STOP Condition

Low to high transition of SDA when SCL is high, terminating all
communications. A STOP condition initiates an EEPROM
programming cycle. A STOP condition after reading a data byte
from the EEPROM initiates the Standby mode.

Acknowledge

A successful reception of eight data bits is indicated by the
receiver by pulling down the SDA line during the following clock
cycle of SCL (ACK). The transmitter on the other hand has to
release the SDA line after the transmission of eight data bits.
The EEPROM as the receiving device responds with an
acknowledge, when addressed. The master, on the other side,
acknowledges each data byte transmitted by the EEPROM and
can at any time end a read operation by releasing the SDA line (no
ACK) followed by a STOP condition.

Data Transfer

Data must change only during low SCL state, data remains valid
on the SDA bus during high SCL state. Nine clock pulses are
required to transfer one data byte, the most significant bit (MSB)
is transmitted first.

ACK

START Condition

Data allowed

STOP Condition

to Change

Acknowledge

SCL

SDA

IED02128

SLx 24C08/16

Semiconductor Group

1998-07-27

Device Addressing and EEPROM Addressing

After a START condition, the master always transmits a Command Byte CSW or CSR.
After the acknowledge of the EEPROM a Control Byte follows, its content and the
transmitter depend on the previous Command Byte. The description of the Command
and Control Bytes is shown in table 2.

The device has an internal address counter which points to the current EEPROM
address.

The address counter is incremented
after a data byte to be written has been acknowledged, during entry of further data

byte

during a byte read, thus the address counter points to the following address after

reading a data byte.

Command Byte

Selects operation: the least significant bit b0 is low for a write
operation (Chip Select Write Command Byte CSW) or set high for a
read operation (Chip Select Read Command Byte CSR).

Contains address information: in the CSW Command Byte, the
bit positions b2 or b3 to b1 are decoded for the two or three
uppermost EEPROM address bits A9 or A10 to A8 (in the CSR
Command Byte, the bit positions b3 to b1 are left undefined).

Control Byte

Following CSW (b0 = 0): contains the eight lower bits of the
EEPROM address (EEA) bit A7 to A0.

Following CSR (b0 = 1): contains the data read out, transmitted by
the EEPROM. The EEPROM data are read as long as the master
pulls down SDA after each byte in order to acknowledge the
transfer. The read operation is stopped by the master by releasing
SDA (no acknowledge is applied) followed by a STOP condition.

Table 2
Command and Control Byte for

C-Bus Addressing of Chip and EEPROM

Definition

Function

CSW

A10 A9 A8 0

Chip Select for Write

CSR

Chip Select for Read

EEA

A7 A6 A5 A4 A3

A2 A1 A0 EEPROM address

SLx 24C08/16

Semiconductor Group

1998-07-27

The timing conventions for read and write operations are described in figures 5 and 6.

Figure 5
Timing of the Command Byte CSW

Figure 6
Timing of the Command Byte CSR

A10 A9

A1 A0 ACK

START from Master

Acknowledge from EEPROM

SCL

SDA

Command Byte (CSW)

Data Transfer to EEPROM

IED02257

ACK

START from Master

Acknowledge from Master

Acknowledge from EEPROM

SCL

SDA

Command Byte (CSR)

Data Transfer from EEPROM

IED02185

ACK

SLx 24C08/16

Semiconductor Group

1998-07-27

Write Operations

Changing of the EEPROM data is initiated by the master with the command byte CSW.
Depending on the state of the Write Protection pin WP either one byte (Byte Write) or up
to 16 bytes (Page Write) are modified in one programming procedure.

5.1

Byte Write

Figure 7
Byte Write Sequence

The erase/write cycle is finished latest after 8 ms. Acknowledge polling may be used for
speed enhancement in order to indicate the end of the erase/write cycle (refer to
chapter 5.3 Acknowledge Polling).

Address Setting

After a START condition the master transmits the Chip Select
Write byte CSW. The EEPROM acknowledges the CSW byte
during the ninth clock cycle. The following byte with the
EEPROM address (A0 to A7) is loaded into the address
counter of the EEPROM and acknowledged by the EEPROM.

Transmission of Data

Finally the master transmits the data byte which is also
acknowledged by the EEPROM into the internal buffer.

Programming Cycle

Then the master applies a STOP condition which starts the
internal programming procedure. The data bytes are written in
the memory location addressed in the EEA byte (A0 to A7)
and the CSW byte (A8 to A9 or A10). The programming
procedure consists of an internally timed erase/write cycle. In
the first step, the selected byte is erased to "1". With the next
internal step, the addressed byte is written according to the
contents of the buffer.

Command Byte

CSW

C
K

S
T
A

EEPROM Address

EEA

Data Byte

Bus Activity
Master

SDA Line

Bus Activity
EEPROM

IED02129

C
K

SLx 24C08/16

Semiconductor Group

1998-07-27

5.2

Page Write

Those bytes of the page that have not been addressed are not included in the
programming.

Figure 8
Page Write Sequence

Address Setting

The page write procedure is the same as the byte write
procedure up to the first data byte. In a page write instruction
however, entry of the EEPROM address byte EEA is followed
by a sequence of one to maximum sixteen data bytes with the
new data to be programmed. These bytes are transferred to
the internal page buffer of the EEPROM.

Transmission of Data

The first entered data byte will be stored according to the
EEPROM address n given by EEA (A0 to A7) and CSW (A8 to
A9 or A10). The internal address counter is incremented
automatically

after

the

entered

data

byte

has

been

acknowledged. The next data byte is then stored at the next
higher EEPROM address. EEPROM addresses within the
same page have common page address bits A4 through A10.
Only the respective four least significant address bits A0
through A3 are incremented, as all data bytes to be
programmed simultaneously have to be within the same page.

Programming Cycle

The master stops data entry by applying a STOP condition,
which also starts the internally timed erase/write cycle. In the
first step, all selected bytes are erased to "1". With the next
internal step, the addressed bytes are written according to the
contents of the page buffer.

Command Byte

CSW

C
K

S
T
A

EEPROM Address

EEA n

Data Byte n

Data Byte n+1

Data Byte n+15

Bus Activity
Master

SDA Line

Bus Activity
EEPROM

IED02140

C
K

SLx 24C08/16

Semiconductor Group

1998-07-27

5.3

Acknowledge Polling

During the erase/write cycle the EEPROM will not respond to a new command byte until
the internal write procedure is completed. At the end of active programming the chip
returns to the standby mode and the last entered EEPROM byte remains addressed by
the address counter. To determine the end of the internal erase/write cycle acknowledge
polling can be initiated by the master by sending a START condition followed by a
command byte CSR or CSW (read with b0 = 1 or write with b0 = 0). If the internal erase/
write cycle is not completed, the device will not acknowledge the transmission. If the
internal erase/write cycle is completed, the device acknowledges the received command
byte and the protocol activities can continue.

Figure 9
Flow Chart "Acknowledge Polling"

Internal Programming

Procedure

Send Start

Send CS-Byte

from EEPROM

Acknowledge

received?

Next Operation

Yes

IED02131

SLx 24C08/16

Semiconductor Group

1998-07-27

Read Operations

Reading of the EEPROM data is initiated by the Master with the command byte CSR.

6.1

Random Read

Random read operations allow the master to access any memory location.

Figure 11
Random Read

Address Setting

The master generates a START condition followed by the
command byte CSW. The receipt of the CSW-byte is
acknowledged by the EEPROM with a low on the SDA line.
Now the master transmits the EEPROM address (EEA) to the
EEPROM and the internal address counter is loaded with the
desired address.

Transmission of CSR

After the acknowledge for the EEPROM address is received,
the master generates a START condition, which terminates
the initiated write operation. Then the master transmits the
command byte CSR for read, which is acknowledged by the
EEPROM.

Transmission of
EEPROM Data

During the next eight clock pulses the EEPROM transmits the
data byte and increments the internal address counter.

STOP Condition from
Master

During the following clock cycle the masters releases the bus
and then transmits the STOP condition.

Command Byte

CSW

A
C

C
K

S
T
A

EEPROM Address

EEA n

Bus Activity
Master

SDA Line

Bus Activity
EEPROM

IED02133

C
K

Data Byte

CSR

Command Byte

SLx 24C08/16

Semiconductor Group

1998-07-27

6.2

Current Address Read

The EEPROM content is read without setting an EEPROM address, in this case the
current content of the address counter will be used (e.g. to continue a previous read
operation after the Master has served an interrupt).

Figure 12
Current Address Read

Transmission of CSR

For a current address read the master generates a START
condition, which is followed by the command byte CSR (chip
select read). The receipt of the CSR-byte is acknowledged by
the EEPROM with a low on the SDA line.

Transmission of
EEPROM Data

During the next eight clock pulses the EEPROM transmits the
data byte and increments the internal address counter.

STOP Condition from
Master

During the following clock cycle the masters releases the bus
and then transmits the STOP condition.

Command Byte

CSR

A
C

S
T
A

Bus Activity
Master

SDA Line

Bus Activity
EEPROM

IED02132

Data Byte

SLx 24C08/16

Semiconductor Group

1998-07-27

6.3

Sequential Read

A sequential read is initiated in the same way as a current read or a random read except
that the master acknowledges the data byte transmitted by the EEPROM. The EEPROM
then continues the data transmission. The internal address counter is incremented by
one during each data byte transmission.

A sequential read allows the entire memory to be read during one read operation. After
the highest addressable memory location is reached, the internal address pointer "rolls
over" to the address 0 and the sequential read continues.

The transmission is terminated by the master by releasing the SDA line (no
acknowledge) and generating a STOP condition (see figure 13).

Figure 13
Sequential Read

Data Byte n

EEPROM

Bus Activity

SDA Line

Master

Bus Activity

CSW

Command Byte

C
K

A
C

Data Byte n+x

Data Byte n+1

C
K

IED02134

SLx 24C08/16

Semiconductor Group

1998-07-27

Electrical Characteristics

The listed characteristics are ensured over the operating range of the integrated circuit.
Typical characteristics specify mean values expected over the production spread. If not
otherwise specified, typical characteristics apply at

= 25

C and the given supply

voltage.

7.1

Absolute Maximum Ratings

Stresses above those listed here may cause permanent damage to the device. This is a
stress rating only and functional operation of the device at these or any other conditions
above those indicated in the operational section of this data sheet is not implied.
Exposure to absolute maximum ratings for extended periods may affect device reliability.

Parameter

Limit Values

Units

Operating temperature

range 1 (industrial)
range 2 (automotive)

40 to + 85
40 to + 125

°C
°C

Storage temperature

65 to + 150

°C

Supply voltage

0.3 to + 7.0

All inputs and outputs with respect to ground

0.3 to

+ 0.5

ESD protection (human body model)

4000

7.2

DC Characteristics

Parameter

Symbol

Limit Values

Units Test Condition

min.

typ. max.

Supply voltage

4.5

5.5

5 V type

2.7

5.5

3 V type

Supply current

(write)

= 5 V;

= 100 kHz

Standby
current

Inputs at

Input leakage
current

0.1

Output leakage
current

0.1

OUT

Input low
voltage

0.3

SLx 24C08/16

Semiconductor Group

1998-07-27

The values for

are maximum peak values

Valid over the whole temperature range

This parameter is characterized only

Input high
voltage

0.7

+ 0.5 V

Output low
voltage

0.4

= 3 mA;

= 5 V

= 2.1 mA;

= 3 V

Input/output
capacitance
(SDA)

I/O

= 0 V;

= 5 V

Input
capacitance
(other pins)

= 0 V;

= 5 V

Capacitive load
for each bus line

400

7.2

DC Characteristics (cont'd)

Parameter

Symbol

Limit Values

Units Test Condition

min.

typ. max.

SLx 24C08/16

Semiconductor Group

1998-07-27

The minimum rise and fall times can be calculated as follows: 20 + (0.1/pF)

[ns]

Example:

= 100 pF

= 20 + 0.1

100 [ns] = 30 ns

7.3

AC Characteristics

Parameter

Symbol

Limit Values

= 2.7-5.5 V

Limit Values

= 4.5-5.5 V

Units

min.

max.

min.

max.

SCL clock frequency

SCL

100

400

kHz

Clock pulse width low

low

4.7

1.2

Clock pulse width high

high

4.0

0.6

SDA and SCL rise time

1000

300

SDA and SCL fall time

300

Start set-up time

SU.STA

4.7

0.6

Start hold time

HD.STA

4.0

0.6

Data in set-up time

SU.DAT

200

100

Data in hold time

HD.DAT

SCL low to SDA data out valid

0.1

4.5

0.1

0.9

Data out hold time

100

Stop set-up time

SU.STO

4.0

0.6

Time the bus must be free before
a new transmission can start

BUF

4.7

1.2

SDA and SCL spike suppression
time at constant inputs

100

7.4

Erase and Write Characteristics

Parameter

Symbol

Limit Values

= 2.7-5.5 V

Limit Values

= 4.5-5.5 V

Units

typ.

max.

typ.

max.

Erase + write cycle (per page)

Erase page protection bit

2.5

Write page protection bit

2.5

Document Outline

Ð­Ð»ÐµÐºÑ‚Ñ€Ð¾Ð½Ð½Ñ‹Ð¹ ÐºÐ¾Ð¼Ð¿Ð¾Ð½ÐµÐ½Ñ‚: Q67100-H3229

Document Outline

ÐÐ»ÐµÐºÑ‚Ñ€Ð¾Ð½Ð½Ñ‹Ð¹ ÐºÐ¾Ð¼Ð¿Ð¾Ð½ÐµÐ½Ñ‚: Q67100-H3229