> 3.13 | I 2C Interface

> I 2C is a serial, 8-bit oriented data transfer bus for bit rates up to 400 kbps in Fast mode. It consists of two lines, the serial data line I2CDAT and the serial clock line I2CCLK.
> The TC65 module acts as a single master device, e.g. the clock I2CCLK is driven by module. I2CDAT is a bi-directional line. Each device connected to the bus is software addressable by a unique 7-bit address, 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 I 2C bus use the AT^SSPI command. If the I2C bus is active the two lines I2CCLK and I2DAT are locked for use as SPI lines. Vice versa, the activation of the SPI locks both lines for I2C. Detailed information on the AT^SSPI command as well explanations on the protocol and syntax required for data transmission can be found in [1].
> The I 2C interface can be powered from an external supply or via the VEXT line of TC65. If connected to the VEXT line the I2C interface will be properly shut down when the module enters the Power-down mode. If you prefer to connect the I2C interface to an external power supply, take care that VCC of the application is in the range of VVEXT and that the interface is shut down when the PWR_IND signal goes high. See figures below as well as Chapter 7 and Figure 51.
> 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 30.
> Figure 20: I 2C interface connected to VCC of application
> Figure 21: I 2C interface connected to VEXT line of TC65
> 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.