MPC8533EVTANG Freescale Semiconductor, MPC8533EVTANG Datasheet - Page 465

• Manufacturer Part Number: MPC8533EVTANG
• Description: MPU POWERQUICC 783-PBGA
• Manufacturer: Freescale Semiconductor

Specifications of MPC8533EVTANG

• Processor Type: MPC85xx PowerQUICC III 32-Bit
• Speed: 800MHz
• Voltage: 1V
• Mounting Type: Surface Mount
• Package / Case: 783-FCPBGA
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Features: -

The I
address is always zero; however the I
broadcast message is the master address. Because the second byte is automatically acknowledged by
hardware, the receiver device software must verify that the broadcast message is intended for itself by
reading the second byte of the message. If the master address is for another receiver device and the third
byte is a write command, software can ignore the third byte during the broadcast. If the master address is
for another receiver device and the third byte is a read command, software must write 0xFF to I2CDR with
I2CCR[TXAK] = 1, so that it does not interfere with the data written from the addressed device.
Each data byte is 8 bits long. Data bits can be changed only while SCL is low and must be held stable while
SCL is high, as shown in
significant bit (msb) is transmitted first. Each byte of data must be followed by an acknowledge bit, which
is signaled from the receiving device by pulling the SDA line low at the 9th clock. Therefore, one complete
data byte transfer takes 9 clock pulses. Several bytes can be transferred during a data transfer session.
If the slave receiver does not acknowledge the master, the SDA line must be left high by the slave. The
master can then generate a stop condition to abort the data transfer or a START condition (repeated
START) to begin a new calling.
If the master receiver does not acknowledge the slave transmitter after a byte of transmission, the slave
interprets that the end-of-data has been reached. Then the slave releases the SDA line for the master to
generate a STOP or a START condition.
11.4.1.3
Figure 11-8
terminate the previous transfer. The master uses this method to communicate with another slave or with
the same slave in a different mode (transmit/receive mode) without releasing the bus.
11.4.1.4
The master can terminate the transfer by generating a STOP condition to free the bus. A STOP condition
is defined as a low-to-high transition of the SDA signal while SCL is high. For more information, see
Figure
at which point the slave must release the bus. The STOP condition is initiated by a software write that
clears I2CCR[MSTA].
As described in
condition followed by a calling address without generating a STOP condition for the previous transfer.
This is called a repeated START condition.
Freescale Semiconductor
2
C module responds to a general call (broadcast) command when I2CCR[BCST] is set. A broadcast
11-8. Note that a master can generate a STOP even if the slave has transmitted an acknowledge bit,
shows a repeated START condition, which is generated without a STOP condition that can
MPC8533E PowerQUICC III Integrated Host Processor Family Reference Manual, Rev. 1
Repeated START Condition
STOP Condition
Section 11.4.1.3, “Repeated START Condition,”
Figure
11-8. There is one clock pulse on SCL for each data bit, and the most
2
C module will not check the R/W bit. The second byte of the
the master can generate a START
I
2
C Interfaces
11-13