Motorola PowerQUICC II MPC8280 Series Reference Manual page 1043

The rate (in cells/second) is calculated as in Figure 31-16.
Initialize the traffic parameters (ER, MCR, PCR, or ICR) in the ABR protocol-specific
connection tables using the rate formula in Figure 31-16.
31.5.3 ABR Flow Control Setup
Follow these steps to setup ABR flow control:
1. Initialize the ABR data structure: RCT, TCT, RCT-ABR protocol-specific,
TCTE-ABR protocol-specific.
2. Initialize ABR global parameters in the parameter RAM. See Section 31.10.1,
"Parameter RAM."
3. Program the AAL-type in the RCT and TCT to AAL5 and set TCT[ABRF].
ABR flow control is available only with AAL5.
4. The time stamp timer generates the RM cell's time stamp, which the ABR flow
control monitors to maintain source behavior in steps #3 and #7 of
Section 31.5.1.1, "ABR Flow Control Source End-System Behavior." Enable the
time stamp timer by writing to the RTSCR; see Section 14.3.8, "RISC Time-Stamp
Control Register (RTSCR)."
5. Initialize the ABR parameters (CPS_ABR and LINE_RATE_ABR) in the APCT;
see Section 31.10.4.1, "APC Parameter Tables." Note that when using ABR, the
CPS (cells per slot) parameter in the APCPT should be a power of two.
6. Finally, send the
31.6 OAM Support
This section describes the MPC8280's 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.
MOTOROLA Chapter 31. ATM Controller and AAL0, AAL1, and AAL5
Freescale Semiconductor, Inc.
⎛
e
×
Rate = 2
⎝
Figure 31-16. Rate Formula for RM Cells
NOTE
command to restart channel transmission.
ATM TRANSMIT
For More Information On This Product,
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⎞
m
×
1 + --------- - nz
⎠
512
OAM Support
31-29