PXS20RM Datasheet, PDF (893/1368 Pages) Freescale Semiconductor, Inc – PXS20 Microcontroller

FlexRay Communication Controller
26.7.7 Message Buffer Search on Simple Message Buffer Configuration
This sections describes the message buffer search behavior for a simplified message buffer configuration.
The FIFO behavior is not considered in this section.
26.7.7.1 Simple Message Buffer Configuration
A simple message buffer configuration is a configuration that has at most one transmit message buffer and
at most one receive message buffer assigned to a slot S. The simple configuration used in this section
utilizes two message buffers, one single buffered transmit message buffer and one receive message buffer.
The transmit message buffer has the message buffer number t and has following configuration
Table 26-137. Transmit Buffer Configuration
Register
Field
Value
Description
FR_MBCCSRt
FR_MBCCFRt
FR_MBFIDRt
MCM
MBT
MTD
MTM
CHA
CHB
CCFE
CCFMSK
CCFVAL
FID
-
0
1
0
1
0
1
000011
000000
S
used only for double buffers
single transmit buffer
transmit buffer
event transition mode
assigned to channel A
not assigned to channel B
cycle counter filter enabled
cycle set = {4n} = {0,4,8,12,...}
assigned to slot S
The availability of data in the transmit buffer is indicated by the commit bit FR_MBCCSRt[CMT] and the
lock bit FR_MBCCSRt[LCKS].
The receive message buffer has the message buffer number r and has following configuration
Table 26-138. Receive Buffer Configuration
Register
FR_MBCCSRr
Field
MCM
MBT
MTD
Value
-
-
0
n/a
n/a
receive buffer
Description
Freescale Semiconductor
PXS20 Microcontroller Reference Manual, Rev. 1
26-181