PXN20RM Datasheet, PDF (706/1376 Pages) Freescale Semiconductor, Inc – PXN20 Microcontroller

FlexRay Communication Controller (FlexRAY)
Table 26-86. Frame Header Field Descriptions (Transmit Message Buffer) (continued)
Field
Description
PLDLEN Payload Length — This field is checked and used as described in Frame Header Checks.
HDCRC Header CRC — This field provides the value of the Header CRC field for the frame transmitted from the message
buffer.
26.6.5.2.2 Data Field Offset Description
Data Field Offset Content
For a detailed description of the Data Field Offset, see Section 26.6.2.1.2, Data Field Offset.
Data Field Offset Access
The application shall program the Data Field Offset when configuring the message buffers either in the
POC:config state or when the message buffer is disabled.
26.6.5.2.3 Slot Status Description
The slot status is a read-only structure for the application and a write-only structure for the controller. The
meaning and content of the slot status in the message buffer header field 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 26-87.
Table 26-87. Receive Message Buffer Slot Status Content
Receive Message Buffer Type
Individual Receive Message Buffer assigned to both channels
MBCCSRn[CHA] = 1 and MBCCSRn[CHB] = 1
Individual Receive Message Buffer assigned to channel A
MBCCSRn[CHA] = 1 and MBCCSRn[CHB] = 0
Individual Receive Message Buffer assigned to channel B
MBCCSRn[CHA] = 0 and MBCCSRn[CHB] = 1
Receive FIFO Channel A Message Buffer
Receive FIFO Channel B Message Buffer
Slot Status Content
see Figure 26-112
see Figure 26-113
see Figure 26-114
see Figure 26-113
see Figure 26-114
The meaning of the bits in the slot status structure is explained in Table 26-88.
26-92
PXN20 Microcontroller Reference Manual, Rev. 1
Freescale Semiconductor