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Chapter 13 FlexRay Communication Controller (FLEXRAY)
MC9S12XF - Family Reference Manual, Rev.1.19
Freescale Semiconductor
551
13.6.5.2.2
Data Field Offset Description
Data Field Offset Content
Data Field Offset Access
The application shall program the Data Field Offset when conguring the message buffers either in the
POC:cong state or when the message buffer is disabled.
13.6.5.2.3
Slot Status Description
The slot status is a read-only structure for the application and a write-only structure for the FlexRay block.
The meaning and content of the slot status in the message buffer header eld depends on the message
buffer type.
Receive Message Buffer and Receive FIFO Slot Status Description
This section describes the slot status structure for the individual receive message buffers and receive
FIFOs. The content of the slot status structure for receive message buffers depends on the message buffer
type and on the channel assignment for individual receive message buffers as given by
Table 13-85.
CYCCNT
Cycle Count
For receive message buffer and receive FIFOs, this eld provides the number of the communication cycle in
which the frame stored in this message buffer was received.
For transmit message buffers, the value of this eld is ignored. The FlexRay block will overwrite this value with
the current cycle count value when it transmits the frame.
PLDLEN
Payload Length in 16-Bit Units
For receive message buffers and receive FIFOs, this eld provides the value of the payload length eld of the
rst valid frame received on the FlexRay bus in the slot indicated by the FID eld.
For transmit message buffers assigned to the static segment, this value is ignored for the frame generation.
The FlexRay block uses the value in the PCR19.paylaod_length_static to set the value of the Payload length
eld in the transmitted frame.
For transmit message buffers assigned to the dynamic segment, this value is used to set the value of the
Payload length eld in the transmitted frame.
Note: The value of this eld is given in numbers of 16-bit units
HDCRC
Header CRC
For receive and FIFO message buffers, this eld provides the value of the Header CRC of the received frame.
For transmit message buffers, this eld provides the Header CRC value as it was given by the application.The
FlexRay block transmits this value in the Header CRC eld of the transmitted frame.
Table 13-84. Frame Header Field Descriptions (continued)
Field
Description