45.3.12 I2C SCL Low Timeout Register Low (I2Cx_SLTL)
Address: Base a Bh offset
Bit
7
6
5
4
3
2
1
0
Read
Write
Reset
0
0
0
0
0
0
0
0
I2Cx_SLTL field descriptions
Field
Description
7–0
SSLT[7:0]
SSLT[7:0]
Least significant byte of SCL low timeout value that determines the timeout period of SCL low.
45.4 Functional description
This section provides a comprehensive functional description of the I2C module.
45.4.1 I2C protocol
The I2C bus system uses a serial data line (SDA) and a serial clock line (SCL) for data
transfers.
All devices connected to it must have open drain or open collector outputs. A logic AND
function is exercised on both lines with external pull-up resistors. The value of these
resistors depends on the system.
Normally, a standard instance of communication is composed of four parts:
1. START signal
2. Slave address transmission
3. Data transfer
4. STOP signal
The STOP signal should not be confused with the CPU STOP instruction. The following
figure illustrates I2C bus system communication.
Functional description
K22F Sub-Family Reference Manual , Rev. 3, 7/2014
1110
Freescale Semiconductor, Inc.