Motorola MPC8260 User Manual
29-27
MPC8260 PowerQUICC II UserÕs Manual
MOTOROLA
Part IV. Communications Processor Module
29.5.3 ABR Flow Control Setup
Follow these steps to setup ABR ßow control:
1. Initialize the ABR data structure: RCT, TCT, RCT-ABR protocol-speciÞc, TCTE-
ABR protocol-speciÞc.
3. Program the AAL-type in the RCT and TCT to AAL5 and set TCT[ABRF]. Note
that the ABR ßow control is available only with AAL5.
4. The time stamp timer generates the RM cellÕs time stamp, which the ABR ßow
control monitors to maintain source behavior in steps #3 and #7 of Section 29.5.1.1,
ÒABR Flow Control Source End-System Behavior.Ó Enable the time stamp timer by
writing to the RTSCR; see Section 13.3.7, ÒRISC Time-Stamp Control Register
(RTSCR).Ó
ÒABR Flow Control Source End-System Behavior.Ó Enable the time stamp timer by
writing to the RTSCR; see Section 13.3.7, ÒRISC Time-Stamp Control Register
(RTSCR).Ó
5. Initialize the ABR parameters (CPS_ABR and LINE_RATE_ABR) in the APCT;
see Section 29.10.4.1, ÒAPC Parameter Tables.Ó Note that when using ABR, the CPS
(cells per slot) parameter in the APCPT should be a power of two.
(cells per slot) parameter in the APCPT should be a power of two.
6. Finally, send the
ATM
TRANSMIT
command to restart channel transmission.
29.6 OAM Support
This section describes the MPC8260Õs support for ATM-layer (F4 out-of-band, and F5 in-
band) operations and maintenance (OAM) of connections. Alarm surveillance, continuity
checking, remote defect indication, and loopback cells are supported using OAM receive
and transmit AAL0 cell queues. Using dedicated support, performance management block
tests can be performed on up to 64 connections simultaneously. The CP automatically
inserts forward monitoring cells (FMC) and generates backward-reporting cells (BRC) as
recommended by ITU I.610.
band) operations and maintenance (OAM) of connections. Alarm surveillance, continuity
checking, remote defect indication, and loopback cells are supported using OAM receive
and transmit AAL0 cell queues. Using dedicated support, performance management block
tests can be performed on up to 64 connections simultaneously. The CP automatically
inserts forward monitoring cells (FMC) and generates backward-reporting cells (BRC) as
recommended by ITU I.610.
29.6.1 ATM-Layer OAM DeÞnitions
Table 29-8 lists pre-assigned header values at the user-network interface (UNI).
Table 29-8. Pre-Assigned Header Values at the UNI
Use
GFC
VPI
VCI
PTI
CLP
Segment OAM F4 ßow cell
xxxx
aaaa_aaaa
0000_0000_0000_0011
0a0
a
End-to-end OAM F4 ßow cell
xxxx
aaaa_aaaa
0000_0000_0000_0100
0a0
a
Segment OAM F5 ßow cell
xxxx
aaaa_aaaa
aaaa_aaaa_aaaa_aaaa
100
a
End-to-end OAM F5 ßow cell
xxxx
aaaa_aaaa
aaaa_aaaa_aaaa_aaaa
101
a
a = available for use by the appropriate ATM layer function