MC912DG128A Motorola, MC912DG128A Datasheet - Page 263

• Manufacturer Part Number: MC912DG128A
• Description: Microcontrollers
• Manufacturer: Motorola

DDRIB — Data Direction for Port IB Register
IIC Programming Examples
Initialization
Sequence
Generation of
START
17-iicbus
MOTOROLA
RESET:
DDRIB7
Bit 7
0
DDRIB6
Read and write anytime
DDRIB[7:2]— Port IB [7:2] Data direction
DDRIB[5:0] — These bits served as memory locations since there are
no corresponding external port pins for MC68HC912DT128A.
Reset will put the IIC Bus Control Register to its default status. Before
the interface can be used to transfer serial data, an initialization
procedure must be carried out, as follows:
After completion of the initialization procedure, serial data can be
transmitted by selecting the 'master transmitter' mode. If the device is
6
0
1. Update the Frequency Divider Register (IBFD) and select the
2. Update the IIC Bus Address Register (IBAD) to define its slave
3. Set the IBEN bit of the IIC Bus Control Register (IBCR) to enable
4. Modify the bits of the IIC Bus Control Register (IBCR) to select
Each bit determines the primary direction for each pin configured as
general-purpose I/O.
0 = Associated pin is a high-impedance input.
1 = Associated pin is an output.
required division ratio to obtain SCL frequency from system clock.
address.
the IIC interface system.
Master/Slave mode, Transmit/Receive mode and interrupt enable
or not.
DDRIB5
5
0
DDRIB4
Inter-IC Bus
4
0
DDRIB3
3
0
DDRIB2
2
0
DDRIB1
MC68HC912DT128A Rev 2.0
IIC Programming Examples
1
0
DDRIB0
Bit 0
0
Inter-IC Bus
$00E7
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