ATM Controller
MPC885 PowerQUICC Family Reference Manual, Rev. 2
Freescale Semiconductor
39-11
Upon receiving terminated FMCs, the CP copies the incoming FMC to the raw cell queue. The CP also
copies TRCC
0
and TRCC
0+1
from the PM table and inserts them into their respective locations in the
incoming FMC. The CP also automatically calculates BER according to the BEDC received in the FMC
and the BEDC
0+1
-Rx in the PM table. The BER is also copied to its respective location in the FMC
payload.
A TRCC is a free-running counter (modulo 65536) that counts user cells received. The total number of
received cells in a particular block is the difference between the TRCC values of two consecutive BRCs.
The host may use the terminated FMC data for PM information gathering and statistics. The host may
optionally generate BRM cells by updating MCSN and time stamp fields and writing 0x6A6A to the
BEDC field. BER should be modified to 0xFF if either of the following apply. (See the ITU
recommendation I.610.)
•
The number of user cells (i.e., CLP=0+1) between the last two forward monitoring OAM cells does
not equal the difference between the TUC values of the last two forward monitoring OAM cells.
•
The MCSN of the last two performance monitoring OAM cells used for forward monitoring are
not sequential.
Figure 39-7 is an example of the MPC885 as an endpoint/segment point. The PM block size is 512 cells.
For every 512 user cells sent, the CP automatically inserts an FMC into the cell stream as defined in the
ITU I.610 recommendation. When an FMC is received and terminated, the CP delivers the terminated cell
to the host in the raw cell queue. The host uses this cell to gather various statistics and may optionally
prepare the BRC and schedule it to be sent back by the transmitter.
Figure 39-7. Example FMC to BRC Turn-around
FMC
Data
FMC
512 User Cell
512 User Cell
TUC0
Incoming
cell Stream
1
2
3
TSTP
BEDC
TUC0+1
TUC0
TSTP
BEDC
TUC0+1
TUC0
TSTP
BEDC
TUC0+1
TUC0
Destination BRC
Transmit Stream
1
TUC0+1
TSTP
BERR
TRCC0
TRCC0+1
TUC0
2
TUC0+1
TSTP
BERR
TRCC0
TRCC0+1
BRC
TUC0
3
TUC0+1
TSTP
BERR
TRCC0
TRCC0+1
MPC885
Cell
Data
Cell
Data
Cell
Data
Cell
FMC
BRC
BRC
Summary of Contents for PowerQUICC MPC870
Page 98: ...MPC885 PowerQUICC Family Reference Manual Rev 2 I 4 Freescale Semiconductor ...
Page 118: ...MPC885 Overview MPC885 PowerQUICC Family Reference Manual Rev 2 1 20 Freescale Semiconductor ...
Page 158: ...The MPC8xx Core MPC885 PowerQUICC Family Reference Manual Rev 2 3 18 Freescale Semiconductor ...
Page 288: ...MPC885 PowerQUICC Family Reference Manual Rev 2 III 4 Freescale Semiconductor ...
Page 554: ...MPC885 PowerQUICC Family Reference Manual Rev 2 V 6 Freescale Semiconductor ...
Page 1090: ...UTOPIA Interface MPC885 PowerQUICC Family Reference Manual Rev 2 43 8 Freescale Semiconductor ...
Page 1312: ...Byte Ordering MPC885 PowerQUICC Family Reference Manual Rev 2 A 8 Freescale Semiconductor ...
Page 1336: ...MPC885 PowerQUICC Family Reference Manual Rev 2 D 16 Freescale Semiconductor ...
Page 1358: ...MPC885 PowerQUICC Family Reference Manual Rev 2 D 38 Freescale Semiconductor ...
Page 1370: ...MPC880 MPC885 PowerQUICC Family Reference Manual Rev 2 E 4 Freescale Semiconductor ...
Page 1386: ...Revision History MPC885 PowerQUICC Family Reference Manual Rev 2 I 2 Freescale Semiconductor ...