LM3S2965_0711 Datasheet, PDF (386/574 Pages) List of Unclassifed Manufacturers – Microcontroller

Inter-Integrated Circuit (I²C) Interface
Figure 15-13. Slave Command Sequence
Idle
Write OWN Slave
Address to
I2CSOAR
Write -------1 to
I2CSCSR
Read I2CSCSR
NO _{TREQ bit=1?}
YES
Write data to
I2CSDR
NO _{RREQ bit=1?}
FBR is
also valid ^YES
Read data from
I2CSDR
15.3
Initialization and Configuration
The following example shows how to configure the I²C module to send a single byte as a master.
This assumes the system clock is 20 MHz.
1. Enable the I²C clock by writing a value of 0x0000.1000 to the RCGC1 register in the System
Control module.
2. Enable the clock to the appropriate GPIO module via the RCGC2 register in the System Control
module.
3. In the GPIO module, enable the appropriate pins for their alternate function using the
GPIOAFSEL register. Also, be sure to enable the same pins for Open Drain operation.
4. Initialize the I²C Master by writing the I2CMCR register with a value of 0x0000.0020.
5. Set the desired SCL clock speed of 100 Kbps by writing the I2CMTPR register with the correct
value. The value written to the I2CMTPR register represents the number of system clock periods
in one SCL clock period. The TPR value is determined by the following equation:
386
November 30, 2007
Preliminary