User's Manual

Table Of Contents

Cinterion

ELS61-AUS Hardware Interface Description

2.1 Application Interface

 ELS61-AUS_HID_v00.031 2016-06-03

Confidential / Preliminary

Page 35 of 102

2.1.9 I

C Interface

C is a serial, 8-bit oriented data transfer bus for bit rates up to 400kbps in Fast mode. It con-

sists of two lines, the serial data line I2CDAT and the serial clock line I2CCLK. The module acts

as a single master device, e.g. the clock I2CCLK is driven by the module. I2CDAT is a bi-direc-

tional line. Each device connected to the bus is software addressable by a unique 7-bit ad-

dress, and simple master/slave relationships exist at all times. The module operates as master-

transmitter or as master-receiver. The customer application transmits or receives data only on

request of the module.

To configure and activate the I2C bus use the AT^SSPI command. Detailed information on the

AT^SSPI command as well explanations on the protocol and syntax required for data transmis-

sion can be found in [1].

The I

C interface can be powered via the V180 line of ELS61-AUS. If connected to the V180

line, the I

C interface will properly shut down when the module enters the Power Down mode.

In the application I2CDAT and I2CCLK lines need to be connected to a positive supply voltage

via a pull-up resistor. For electrical characteristics please refer to Table 2.

Figure 14: I

C interface connected to V180

Note: Good care should be taken when creating the PCB layout of the host application: The

traces of I2CCLK and I2CDAT should be equal in length and as short as possible.

I2CCLK

I2CDAT

GND

I2CCLK

I2CDAT

GND

Module Application

V180

R pull up