mc68hc908sr12 Freescale Semiconductor, Inc, mc68hc908sr12 Datasheet - Page 295

• Manufacturer Part Number: mc68hc908sr12
• Description: M68hc08 Microcontrollers Microcontroller
• Manufacturer: Freescale Semiconductor, Inc

17.5 Multi-Master IIC System Configuration
17.6 Multi-Master IIC Bus Protocol
MC68HC908SR12•MC68HC08SR12 — Rev. 5.0
Freescale Semiconductor
SDA
SDA
SCL
SCL
START
START
signal
signal
MSB
MSB
1
1
Figure 17-2. Multi-Master IIC Bus Transmission Signal Diagram
1
1
0
0
The multi-master IIC system uses a serial data line SDA and a serial
clock line SCL for data transfer. All devices connected to it must have
open collector (drain) outputs and the logical-AND function is performed
on both lines by two pull-up resistors.
Normally a standard communication is composed of four parts:
These are described briefly in the following sections and illustrated in
Figure
0
0
1. START signal,
2. slave address transmission,
3. data transfer, and
4. STOP signal.
0
0
17-2.
0
0
Multi-Master IIC Interface (MMIIC)
1
1
LSB
9th clock pulse
LSB
1
1
ACK
ACK
Repeated
START
signal
MSB
MSB
1
1
1
1
Data must be stable
when SCL is HIGH
Multi-Master IIC System Configuration
0
0
Multi-Master IIC Interface (MMIIC)
1
1
0
0
0
0
1
1
9th clock pulse
LSB
LSB
1
1
No ACK
No ACK
Data Sheet
STOP
signal
STOP
signal
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