MC68376BGMAB20 Freescale Semiconductor, MC68376BGMAB20 Datasheet - Page 269

• Manufacturer Part Number: MC68376BGMAB20
• Description: IC MCU 32BIT 8K ROM 160-QFP
• Manufacturer: Freescale Semiconductor
• Series: M683xxr

Specifications of MC68376BGMAB20

• Core Processor: CPU32
• Core Size: 32-Bit
• Speed: 20MHz
• Connectivity: CAN, EBI/EMI, SCI, SPI
• Peripherals: POR, PWM, WDT
• Number Of I /o: 18
• Program Memory Type: ROMless
• Ram Size: 7.5K x 8
• Voltage - Supply (vcc/vdd): 4.75 V ~ 5.25 V
• Data Converters: A/D 16x10b
• Oscillator Type: External
• Operating Temperature: -40°C ~ 125°C
• Package / Case: 160-QFP
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Eeprom Size: -
• Program Memory Size: -

13.5.3.1 Transmit Message Buffer Deactivation
13.5.3.2 Reception of Transmitted Frames
13.5.4 Receive Process
MC68336/376
USER’S MANUAL
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 mes-
sage buffer is updated and a status flag is set in the IFLAG register.
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.
While a message is being transferred from a transmit message buffer to a serial mes-
sage buffer, if the user deactivates that transmit message buffer, the message will not
be transmitted.
If the user deactivates the transmit message buffer after the message is transferred to
the serial message buffer, the message will be transmitted, but no interrupt will be
requested and the transmit code will not be updated.
If a message buffer containing the lowest ID is deactivated while that message is un-
dergoing the internal arbitration process to determine which message should be sent,
then that message may not be transmitted.
The TouCAN will receive a frame it has transmitted if an empty message buffer with a
matching identifier exists.
The receive process includes configuring message buffers for reception, the transfer
of received messages by the TouCAN from the serial message buffers to the receive
message buffers with matching IDs, and the retrieval of these messages by the user.
The user should prepare/change a message buffer for frame reception by executing
the following steps.
Once these steps are performed, the message buffer functions as an active receive
buffer and participates in the internal matching process, which takes place every time
the TouCAN receives an error-free frame. In this process, all active receive buffers
compare their ID value to the newly received one. If a match is detected, the following
actions occur:
1. Write the control/status word to hold the receive buffer inactive (code = %0000).
2. Write the ID_HIGH and ID_LOW words.
3. Write the control/status word to mark the receive message buffer as active and
empty.
Steps 1 and 3 are mandatory for data coherency while preparing a
message buffer for reception.
CAN 2.0B CONTROLLER MODULE (TouCAN)
NOTE
MOTOROLA
13-13