mfr4300 Freescale Semiconductor, Inc, mfr4300 Datasheet - Page 177

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

Each message buffer list is sorted according to the priorities given in
highest priority, the message buffer with the lowest message buffer number is selected. For this message
buffer the corresponding transition given in
search.
1
3.4.7.1
The message buffer search identifies the matching message buffers by applying two individual message
buffer filter. The first filter is the frame ID filter, the second filter is the cycle count filter.
3.4.7.1.1
The message buffer frame ID filter is used to determine if the message buffer can be considered for
reception or transmission in a certain slot on a per channel basis.
The frame ID filter matches for a message buffer with message buffer number n and the search slot s, if
the value of the FID field in the
Only message buffer with a frame ID filter match may appear in the matching message buffer list. All
transmit message buffer with a matching frame ID will appear in the matching message buffer list. Only
receive message buffer with a matching frame ID and a matching cycle counter filter will appear in the
matching message buffer list.
3.4.7.1.2
The message buffer cycle counter filter is a value-mask filter defined by the CCFE, CCFMSK, and
CCFVAL fields in the
a set of communication cycles in which the message buffer is considered for message reception or message
transmission. If the cycle counter filter is disabled, i.e. CCFE = ‘0’, this set of cycles consists of all
communication cycles.
If the cycle counter filter of a message buffer does not match a certain communication cycle number, this
message buffer is not considered for message transmission or reception in that communication cycle. In
case of a transmit message buffer, though, this buffer is added to the matching message buffer list with
Freescale Semiconductor
(highest) 0
(lowest) 4
Priority
Cycle Counter Filter Match, see
1
2
3
MTD
Individual Message Buffer Filtering
1
1
1
1
0
0
Message Buffer Frame ID Filtering
Message Buffer Cycle Counter Filtering
MBCCSRn
LCKS
0
0
1
x
0
1
Message Buffer Cycle Counter Filter Registers
CMT
1
0
0
1
x
x
Section 3.4.7.1.2, “Message Buffer Cycle Counter Filtering”
Table 3-107. Message Buffer Search Priority
Message Buffer Frame ID Registers (MBFIDRn)
CCFM
1
1
1
0
1
1
1
MFR4300 Data Sheet, Rev. 3
transmit buffer, unlocked, committed, matches cycle count
transmit buffer, locked or uncommitted, matches cycle count
transmit buffer, assigned to slot
receive buffer, unlocked, matches cycle count
receive buffer, locked, matches cycle count
Table 3-107
is triggered as the result of the message buffer
Description
Table
(MBCCFRn). This filter determines
3-107. From the group with the
FlexRay Module (FLEXRAYV2)
equals s.
Transition
MA
SA
SA
SA
SB
SB
177