mfr4300 Freescale Semiconductor, Inc, mfr4300 Datasheet - Page 168

• Manufacturer Part Number: mfr4300
• Description: Flexray Communication Controllers
• Manufacturer: Freescale Semiconductor, Inc

FlexRay Module (FLEXRAYV2)
FlexRay module to transmit the message data to the FlexRay bus. The two sides are located in adjacent
individual message buffers. The message buffer that implements the commit side has an even message
buffer number 2n. The transmit side message buffer follows the commit side message buffer and has the
message buffer number 2n+1. The basic structure and data flow of a double transmit message buffer is
given in
3.4.6.4.1
To certain message buffer fields, both the application and the FlexRay module have access. To ensure data
consistency, a message buffer locking scheme is implemented, which controls the exclusive access to the
data, control, and status bits of the message buffer.
The access scheme for double transmit message buffers is depicted in
represent fields that can be accessed from both the application and the FlexRay module and, thus, require
access restrictions. A description of the regions is given in
168
CFG
MSG
message data
Application
Figure
MBCCSR[2n]n.CMT
Message Buffer Data Field: DATA[0-N]
Message Buffer Header Field: Slot Status
Message Buffer Header Field: Frame Header
Message Buffer Header Field: Data Field Offset
MBIDXR[2n].MBIDX
MBCCSR[2n].MBT/MTD
MBCCFR[2n].MTM/CHA/CHB/CCF*
MBFIDR[2n].FID
Both the commit and the transmit side must be configured with identical
values except for the
Access Regions
3-121.
Figure 3-122. Double Transmit Message Buffer Access Regions Layout
Commit Side
Figure 3-121. Double Transmit Buffer Structure and Data Flow
MB# 2n
Commit Side
Message Buffer Index Registers
MFR4300 Data Sheet, Rev. 3
Internal Message
message data
Transfer
NOTE
ITX
SS
CFG
Table
Message Buffer Header Field: Frame Header
Message Buffer Header Field: Data Field Offset
MBIDXR[2n+1].MBIDX
MBCCSR[2n+1].CMT
Message Buffer Data Field: DATA[0-N]
Message Buffer Header Field: Slot Status
MBCCSR[2n+1].MBT/MTD
MBCCFR[2n+1].MTM/CHA/CHB/CCF*
MBFIDR[2n+1].FID
MB# 2n+1
3-101.
Transmit Side
(MBIDXRn).
Figure
Transmit Side
3-122. The given regions
Freescale Semiconductor
message data
FlexRay Bus
TX
SS
SR