mc9s12xf512 Freescale Semiconductor, Inc, mc9s12xf512 Datasheet - Page 557

• Manufacturer Part Number: mc9s12xf512
• Description: S12x Microcontrollers 16-bit Automotive Microcontroller
• Manufacturer: Freescale Semiconductor, Inc

13.6.6
The FlexRay block provides three basic types of individual message buffers:
Before an individual message buffer can be used, it must be configured by the application. After the initial
configuration, the message buffer can be reconfigured later. The set of the configuration data for individual
message buffers is given in
13.6.6.1
The individual message buffer configuration consists of two steps. The first step is the allocation of the
required amount of memory for the FRM. The second step is the programming of the message buffer
configuration registers, which is described in this section.
13.6.6.1.1
One part of the message buffer configuration data is common to all individual message buffers and the
receive shadow buffers. These data can only be set when the protocol is in the
The application configures the number of utilized individual message buffers by writing the message
buffer number of the last utilized message buffer into the LAST_MB_UTIL field in the
Segment Size and Utilization Register
Freescale Semiconductor
DATA[0:N-1] Message Data — Provides the message data received or to be transmitted.
NMV[0:11]
MID[0:1]
Field
1. Single Transmit Message Buffers
2. Double Transmit Message Buffers
3. Receive Message Buffers
Individual Message Buffer Functional Description
For receive message buffer and receive FIFOs, this field provides the message data received for this message
buffer.
For transmit message buffers, the field provides the message data to be transmitted.
Message Identifier — If the payload preamble bit PPI is set in the message buffer frame header, the MID field
holds the message ID of a dynamic frame located in the message buffer. The receive FIFO filter uses the
received message ID for message ID filtering.
Network Management Vector — If the payload preamble bit PPI is set in the message buffer frame header, the
network management vector field holds the network management vector of a static frame located in the message
buffer.
Note: The MID and NMV bytes replace the corresponding DATA bytes.
Individual Message Buffer Configuration
DATA, MID, NMV
Common Configuration Data
Field
Section 13.6.3.4.1, “Individual Message Buffer Configuration
Table 13-90. Frame Data Write Access Constraints
POC:config
Table 13-91. Frame Data Field Descriptions
MC9S12XF - Family Reference Manual, Rev.1.19
single buffered
or MB_LCK
(MBSSUTR).
or MB_DIS
POC:config
Description
commit side
or MB_LCK
Chapter 13 FlexRay Communication Controller (FLEXRAY)
or MB_DIS
double buffered
POC:config
transmit side
POC:config
or MB_DIS
Message Buffer
Data”.
state.
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