mcf5407 Freescale Semiconductor, Inc, mcf5407 Datasheet - Page 246

• Manufacturer Part Number: mcf5407
• Description: Mcf5407 Coldfire Integrated Microprocessor User
• Manufacturer: Freescale Semiconductor, Inc

I
next byte data receiving. In slave mode, the same function is available after it is addressed.
8.6 I
The following examples show programming for initialization, signalling START,
post-transfer software response, signalling STOP, and generating a repeated START.
8.6.1 Initialization Sequence
Before the interface can transfer serial data, registers must be initialized, as follows:
8.6.2 Generation of START
After completion of the initialization procedure, serial data can be transmitted by selecting
the master transmitter mode. On a multiple-master bus system, IBSR[IBB] must be tested
to determine whether the serial bus is free. If the bus is free (IBB = 0), the START signal
and the first byte (the slave address) can be sent. The data written to the data register
comprises the address of the desired slave and the lsb indicates the transfer direction.
8-10
2
C Programming Examples
1. Set IFDR[IC] to obtain SCL frequency from the system bus clock. See
2. Update the IADR to define its slave address.
3. Set I2CR[IEN] to enable the I
4. Modify the I2CR to select master/slave mode, transmit/receive mode, and
Section 8.5.2, “I2C Frequency Divider Register (IFDR).”
interrupt-enable or not.
2
Address
C Programming Examples
Reset
Field
R/W
If IBSR[IBB] when the I
following code sequence before proceeding with normal
initialization code. This issues a STOP command to the slave
device, placing it in idle state as if it were just power-cycled on.
I2CR = 0x0
I2CR = 0xA
dummy read of I2DR
IBSR = 0x0
I2CR = 0x0
7
Figure 8-9. I
6
MCF5407 User’s Manual
5
2
2
C bus interface system.
C Data I/O Register (I2DR)
2
C bus module is enabled, execute the
NOTE:
MBAR + 0x290
4
0000_0000
Read/Write
D
3
2
1
0