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Chapter 13 FlexRay Communication Controller (FLEXRAY)
MC9S12XF - Family Reference Manual, Rev.1.19
478
Freescale Semiconductor
13.5.2.9
Message Buffer Segment Size and Utilization Register (MBSSUTR)
Write: POC:cong
This register is used to dene the last individual message buffer that belongs to the rst message buffer
segment and the number of the last used individual message buffer.
13.5.2.10 Protocol Operation Control Register (POCR)
Table 13-15. MBDSR Field Descriptions
Field
Description
14–8
MBSEG2DS
Message Buffer Segment 2 Data Size — The eld denes the size of the message buffer data section in two-
byte entities for message buffers within the second message buffer segment.
6–0
MBSEG1DS
Message Buffer Segment 1 Data Size — The eld denes the size of the message buffer data section in two-
byte entities for message buffers within the rst message buffer segment.
Module Base + 0x000E
15
14
13
12
11
10
9876543210
R
000
LAST_MB_SEG1
000
LAST_MB_UTIL
W
Reset
0001111100011111
Figure 13-9. Message Buffer Segment Size and Utilization Register (MBSSUTR)
Table 13-16. MBSSUTR Field Descriptions
Field
Description
12–8
LAST_MB_SEG1
Last Message Buffer In Segment 1 — This eld denes the message buffer number of the last individual
message buffer that is assigned to the rst message buffer segment. The individual message buffers in the
rst segment correspond to the message buffer control registers MBCCSRn, MBCCFRn, MBFIDRn,
MBIDXRn with n <= LAST_MB_SEG1. The rst message buffer segment contains LAST_MB_SEG1+1
individual message buffers.
Note: The rst message buffer segment contains at least one individual message buffer.
The individual message buffers in the second message buffer segment correspond to the message buffer
control registers MBCCSRn, MBCCFRn, MBFIDRn, MBIDXRn with LAST_MB_SEG1 < n < 32.
Note: If LAST_MB_SEG1 = 31 all individual message buffers belong to the rst message buffer segment
and the second message buffer segment is empty.
4–0
LAST_MB_UTIL
Last Message Buffer Utilized — This eld denes the message buffer number of last utilized individual
message buffer. The message buffer search engine examines all individual message buffer with a message
buffer number n <= LAST_MB_UTIL.
Note: If LAST_MB_UTIL=LAST_MB_SEG1 all individual message buffers belong to the rst message
buffer segment and the second message buffer segment is empty.
Module Base + 0x0014
15
14
13
12
11
10
9876543210
R
0000
EOC_AP
ERC_AP
BSY
0
POCCMD
W WME
WMC
Reset
0000000000000000
Figure 13-10. Protocol Operation Control Register (POCR)