MFR4200 FlexRay Communication Controller
MFR4200 Data Sheet, Rev. 0
124
Freescale Semiconductor
3.2.3.6.15
Even Measurement Counter Register (EMCR)
Address 0x33C
Reset
undefined state
The EMCR and OMCR are described in the following section.
3.2.3.6.16
Odd Measurement Counter Register (OMCR)
Address 0x33E
Reset
undefined state
The EMCR and OMCR hold the number of valid sync frames received during the static segment of an even
or odd cycle, respectively. If sync frame filtering is enabled, only sync frames that have passed the sync
frame rejection and/or acceptance filters (see
Section 3.2.3.8.3, “Sync Frame Rejection Filter Register
(SYNFRFR)
” and
Section 3.2.3.8.1, “Sync Frame Acceptance Filter Value Register (SYNFAFVR)
”) are
considered. The EMCR and OMCR registers hold the number of valid measurements in the measurement
tables (see
Section 3.2.3.6.9, “Odd Sync Frame ID n Register, n = [0:15] (OSFIDnR)
” and
Section 3.2.3.6.11, “Odd Measurement Channel A n Register, n = [0:15] (OMAnR)
”). For example, if the
value of EMCR is two, then two valid sync frames are available for clock sync calculations; the remaining
fourteen values in the measurement table for the even cycle are invalid and may have undefined content.
The EMCR and OMCR counters are incremented each time, when a valid sync frame has been received
on at least one of the channels.
EMCR and OMCR are reset when the CC enters the initialize schedule and coldstart collision resolution
states. In the normal active state and the normal passive state, EMCR is reset in the NIT of the odd cycle,
and OMCR is reset at the end of the even cycle. If the node is a non sync node, EMCR and OMCR are
15
14
13
12
11
10
9
8
Reserved
Reserved
Reserved
Reserved
Reserved
Reserved
Reserved
Reserved
r
r
r
r
r
r
r
r
7
6
5
4
3
2
1
0
Reserved
Reserved
Reserved
Reserved
EMC3
EMC2
EMC1
EMC0
r
r
r
r
rh
rh
rh
rh
Figure 3-87. Even Measurement Counter Register
15
14
13
12
11
10
9
8
Reserved
Reserved
Reserved
Reserved
Reserved
Reserved
Reserved
Reserved
r
r
r
r
r
r
r
r
7
6
5
4
3
2
1
0
Reserved
Reserved
Reserved
Reserved
OMC3
OMC2
OMC1
OMC0
r
r
r
r
rh
rh
rh
rh
Figure 3-88. Odd Measurement Counter Register