mc68hc912dg128 Freescale Semiconductor, Inc, mc68hc912dg128 Datasheet - Page 276

• Manufacturer Part Number: mc68hc912dg128
• Description: M68hc12 Microcontrollers
• Manufacturer: Freescale Semiconductor, Inc

Inter-IC Bus
15.4 IIC System Configuration
15.5 IIC Protocol
Technical Data
276
SDA
SCL
SDA
SCL
Signal
Signal
Start
Start
MSB
MSB
AD7 AD6 AD5 AD4 AD3 AD2 AD1 R/W
AD7 AD6 AD5 AD4 AD3 AD2 AD1 R/W
1
1
2
2
Calling Address
Calling Address
3
3
The 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 drain
or open collector outputs. Logic “and” function is exercised on both lines
with external pull-up resistors, the value of these resistors is system
dependent.
Normally, a standard communication is composed of four parts: START
signal, slave address transmission, data transfer and STOP signal. They
are described briefly in the following sections and illustrated in
2.
4
4
Freescale Semiconductor, Inc.
Figure 15-2. IIC Transmission Signals
5
5
For More Information On This Product,
6
6
7
7
Go to: www.freescale.com
Read/
Write
Read/
Write
LSB
LSB
8
8
Ack
Ack
Bit
Inter-IC Bus
9
9
Bit
XX
Repeated
XXX
Signal
Start
MSB
MSB
AD7 AD6 AD5 AD4 AD3 AD2 AD1 R/W
D7
1
1
D6
2
2
New Calling Address
D5
3
3
Data Byte
D4
4
4
D3
5
5
MC68HC912DG128 — Rev 3.0
D2
6
6
D1
7
7
Read/
Write
LSB
LSB
D0
8
8
Ack
No
Bit
Ack
9
No
9
Bit
MOTOROLA
Signal
Figure 15-
Stop
Signal
Stop