PXR40RM Datasheet, PDF (682/1434 Pages) Freescale Semiconductor, Inc – PXR40 Microcontroller

FlexRay Communication Controller (FLEXRAY)
CFG
MSG
Message Buffer Header Field: Frame Header
Message Buffer Header Field: Data Field Offset
MBIDXRn[MBIDX]
MBCCSRn[CMT]
Message Buffer Data Field: DATA[0-N]
Message Buffer Header Field: Slot Status
MBCCSRn[MBT/MTD]
MBCCFRn[MTM/CHA/CHB/CCF*]
MBFIDRn[FID]
NF
TX
CMT
SR
Figure 22-119. Single Transmit Message Buffer Access Regions
Table 22-95. Single Transmit Message Buffer Access Regions Description
Region
Access from
Application
Module
Region used for
CFG
MSG
NF
TX
CM
SR
read/write
read/write
-
-
-
-
-
-
read-only
read/write
read-only
read-only
Message Buffer Configuration
Message Data and Slot Status Access
Message Header Access for Null Frame Transmission
Message Transmission and Slot Status Update
Message Buffer Validation
Message Buffer Search
The trigger bits MBCCSRn[EDT] and MBCCSRn[LCKT], and the interrupt enable bit
MBCCSRn[MBIE] are not under access control and can be accessed from the application at any time. The
status bits MBCCSRn[EDS] and MBCCSRn[LCKS] are not under access control and can be accessed
from the controller at any time.
The interrupt flag MBCCSnR[MBIF] is not under access control and can be accessed from the application
and the controller at any time. controller clear access has higher priority.
The controller restricts its access to the regions depending on the current state of the message buffer. The
application must adhere to these restrictions in order to ensure data consistency. The transmit message
buffer states are given in Figure 22-120. A description of the states is given in Table 22-96, which also
provides the access scheme for the access regions.
The status bits MBCCSRn[EDS] and MBCCSRn[LCKS] provide the application with the required
message buffer status information. The internal status information is not visible to the application.
22.6.6.2.2 Message Buffer States
This section describes the transmit message buffer states and provides a state diagram.
22-98
PXR40 Microcontroller Reference Manual, Rev. 1
Freescale Semiconductor