mcf5407 Freescale Semiconductor, Inc, mcf5407 Datasheet - Page 239

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

These registers are described in Section 8.5, “Programming Model.”
8.3 I
The I
For I
open collector outputs. (There is no such requirement for inputs.) The logic AND function
is exercised on both lines with external pull-up resistors.
Out of reset, the I
or responding to a slave transmit address, the I
receiver state. See Section 8.6.1, “Initialization Sequence,” for exceptions.
8.4 I
Normally, a standard communication is composed of the following parts:
1. START signal—When no other device is bus master (both SCL and SDA lines are
2. Slave address transmission—The master sends the slave address in the first byte
SCL
A
SDA
2
2
C compliance, all devices connected to these two signals must have open drain or
C module uses a serial data line (SDA) and a serial clock line (SCL) for data transfer.
START
Signal
at logic high), a device can initiate communication by sending a START signal (see
A in Figure 8-2). A START signal is defined as a high-to-low transition of SDA
while SCL is high. This signal denotes the beginning of a data transfer (each data
transfer can be several bytes long) and awakens all slaves.
after the START signal (B). After the seven-bit calling address, it sends the R/W bit
(C), which tells the slave data transfer direction.
2
2
AD7 AD6 AD5 AD4 AD3 AD2 AD1 R/W
C System Configuration
C Protocol
msb
1
The I
I
protocol, and restrictions, see The I
Version 2.1.
2
2
C bus protocol. For information on system configuration,
Calling Address
2
Figure 8-2. I
3
C default is as slave receiver. Thus, when not programmed to be a master
2
C module is designed to be compatible with the Philips
B
4
5
6
2
C Standard Communication Protocol
7
Chapter 8. I
R/W ACK
lsb
8
C
Bit
9
NOTE:
D
XXX
2
C Module
2
C module should return to the default slave
msb
D7 D6 D5
1
E
2
C Bus Specification,
2
3
Data Byte
D4 D3 D2 D1 D0
4
5
I
2
C System Configuration
6
7
lsb
8
ACK
No
Bit
9
STOP
Signal
F
8-3