EAeDIP240-7

Page 7

Specifications may be changed without

prior notice. Printing error reserved

I²C BUS INTERFACE

Wiring the display as shown below allows the display to be operated directly on an I²C bus.

4 different base addresses and 8

different slave addresses can be

selected at the display.

A data transmission rate of up to

100kHz is possible.

If transmitter will pause for min.

100 µs between each byte, SCL

may rise u to max. 400 kHz.

Pinout eDIP240-7

I²C-Bus mode

Pin

Symbol

In/Out Function

Pin Symbol Function

1

GND

-

Ground Potential for logic (0V)

21

N.C.

not connected

2

VDD

-

Power supply for logic (+5V)

22

N.C.

not connected

3

VADJ

In

Operating voltage for LC driving

(input)

23

N.C.

not connected

4

VOUT

Out

Output voltage for LC driving

24

N.C.

not connected

5

RESET

-

L: Reset

25

N.C.

not connected

6

BA0

In

Basic Address 0

26

N.C.

not connected

7

BA1

In

Basic Address 1

27

N.C.

not connected

8

SA0

In

Slave Address 0

28

N.C.

not connected

9

SA1

In

Slave Address 1

29

N.C.

not connected

10

SA2

In

Slave Address 2

30

N.C.

not connected

11

BA2

In

Basic Address 2 (V1.3 or later)

31

N.C.

not connected

12 I2CMODE

In

connect to GND for I²C interface

32

N.C.

not connected

13

DPOM

In

L: disable Power-On-Macro

do not connect for normal operation

33

N.C.

not connected

14

SDA

Bidir. Serial Data Line

34

N.C.

not connected

15

SCL

In

Serial Clock Line

35

N.C.

not connected

16

BUZZ

Out

Buzzer output

36

N.C.

not connected

17 EEP_SDA

Bidir. Serial Data Line for int. EEPROM

37

N.C.

not connected

18 EEP_SCL

Out

Serial Clock Line for int. EEPROM

38

N.C.

not connected

19

EEP_WP

In

H: Write Protect for int. EEPROM

39

N.C.

not connected

20

TEST

SBUF

IN

Out

open-drain with internal pullup 20..50k

IN (Power-On) L: Testmode

OUT L: data in sendbuffer

40

N.C.

not connected

Note:

At pin 20 (SBUF), the display sets a low

level to indicate that data is available to be

fetched from the internal send buffer. This

line can, for instance, be connected to an

interrupt input of the host system.

Application example

I²C - Address

Pin 11,7,6

Base

address

I²C address

BA2 BA1 BA0

D7

D6

D5

D4

D3

D2

D1

D0

L

L

L

$10

0

0

0

1

S

A

2

S

A

1

S

A

0

R

W

LL

H

$20

0

0

1

0

L

H

L

$30

0

0

1

1

L

H

H

$40

0

1

0

0

H

L

L

$70

0

1

1

1

H

L

H

$90

1

0

0

1

HH

L

$B0

1

0

1

1

H

H

H

$D0

1

1

0

1

Note:

The pins BA0 to 2, SA0 to 2, DPOM, DPROT and TEST/SBUF have an internal pullup, which is why only the LO level

(L=0=GND) is to be actively applied. These pins must be left open for a Hi level (H=1).

On pin 20 (SBUF) the display indicates with a low level that data is ready to be retrieved from the internal send buffer.

The line can be connected to an interrupt input of the host system, for example.

all pins open: Write $DE

Read $DF

DATA TRANSFER I²C-BUS

principle I2C-bus transfer:

- I²C-Start

- Master-Transmit: EA eDIP-I²C-address (e.g. $DE), send smallprotocol package (data)

- I²C-Stop

- I²C-Start

- Master-Read: EA eDIP-I²C-Address (e.g. $DF), read ACK-byte and opt. smallprotocoll package (data)

- I²C-Stop

Read

operation:

for

internal

operation the EA eDIP240-7 does

need a short time before providing

the data; therefore a short pause of

min. 6µs is needed for each byte (no

activity of SCL line).