MPC561MZP56 Freescale, MPC561MZP56 Datasheet - Page 708

• Manufacturer Part Number: MPC561MZP56
• Manufacturer: Freescale

Specifications of MPC561MZP56

• Cpu Family: MPC56x
• Device Core: PowerPC
• Device Core Size: 32b
• Frequency (max): 56MHz
• Interface Type: QSPI/SCI/SPI/UART
• Total Internal Ram Size: 32KB
• # I/os (max): 56
• Number Of Timers - General Purpose: 22
• Operating Supply Voltage (typ): 2.6/5V
• Operating Supply Voltage (max): 2.7/5.25V
• Operating Supply Voltage (min): 2.5/4.75V
• On-chip Adc: 2(32-chx10-bit)
• Instruction Set Architecture: RISC
• Operating Temp Range: -40C to 125C
• Operating Temperature Classification: Automotive
• Mounting: Surface Mount
• Pin Count: 388
• Package Type: BGA
• Program Memory Type: ROMLess
• Program Memory Size: Not Required
• Lead Free Status / RoHS Status: Not Compliant

CAN 2.0B Controller Module
The user should prepare or change a message buffer for transmission by executing the following steps.
Once an active transmit code is written to a transmit message buffer, that buffer begins participating in an
internal arbitration process as soon as the receiver senses that the CAN bus is free, or at the inter-frame
space. If there are multiple messages awaiting transmission, this internal arbitration process selects the
message buffer from which the next frame is transmitted.
When this process is over and a message buffer is selected for transmission, the frame from that message
buffer is transferred to the serial message buffer for transmission.
The TouCAN transmits no more than eight data bytes, even if the transmit length contains a value greater
than eight.
At the end of a successful transmission, the value of the free-running timer (which was captured at the
beginning of the identifier field on the CAN bus), is written into the time stamp field in the message buffer.
The code field in the control/status word of the message buffer is updated and a status flag is set in the
IFLAG register.
16.4.3.1
Any write access to the control/status word of a transmit message buffer during the process of selecting a
message buffer for transmission immediately deactivates that message buffer, removing it from the
transmission process.
If the transmit message buffer is deactivated while a message is being transferred from it to a serial
message buffer, the message is not transmitted.
If the transmit message buffer is deactivated after the message is transferred to the serial message buffer,
the message is transmitted, but no interrupt is requested, and the transmit code is not updated.
If a message buffer containing the lowest ID is deactivated while that message is undergoing the internal
arbitration process to determine which message should be sent, then that message may not be transmitted.
16.4.3.2
The TouCAN receives a frame it has transmitted if an empty message buffer with a matching identifier
exists.
16.4.4
During the receive process, the following events occur:
16-14
1. Write the control/status word to hold the transmit buffer inactive (code = 0b1000)
2. Write the ID_HIGH and ID_LOW words
3. Write the data bytes
4. Write the control/status word (active Tx code, Tx length)
Receive Process
Transmit Message Buffer Deactivation
Reception of Transmitted Frames
Steps 1 and 4 are mandatory to ensure data coherency.
MPC561/MPC563 Reference Manual, Rev. 1.2
NOTE
Freescale Semiconductor