Motorola PowerQUICC II MPC8280 Series Reference Manual page 1077

0 1
Offset + 0x00
Offset + 0x02
Offset + 0x04
Offset + 0x06 TUAR —
Offset + 0x08
Offset + 0x0A
Offset + 0x0C
Offset + 0x0E ACRC
Offset + 0x10
Offset + 0x12
Offset + 0x14 FRST
Offset + 0x16
Offset + 0x18
Offset + 0x1A
Offset + 0x1C
Offset + 0x1E
Table 31-27 describes ABR-specific TCTE fields.
Table 31-27. ABR-Specific TCTE Field Descriptions
Offset Bits Name
0x00 — ER-TA Explicit rate–turn-around cell. Holds the ER of the last received F-RM cell. If another F-RM
cell arrives before the previous F-RM cell was turned around, this field is overwritten by the
new RM cell's ER.
0x02 — CCR-TA Current cell rate–turn-around cell. Holds the CCR of the last received F-RM cell. If another
F-RM cell arrives before the previous F-RM cell was turned around, this field is overwritten
by the new RM cell's CCR.
0x04 — MCR-TA Minimum cell rate–turn-around cell. Holds the MCR of the last received F-RM cell. If
another F-RM cell arrives before the previous F-RM cell is turned around, this field is
overwritten by the new RM cell's MCR.
0x06 0 TUAR Turn-around flag. The CP sets TUAR to indicate that a new F-RM cell was received, which
causes the transmitter to send a B-RM cell whenever the ABR flow control permits. Should
be cleared initially.
1 — Reserved, should be cleared.
2 CI-TA Congestion indication–turn-around cell. Holds the CI of the last received F-RM cell. If
another F-RM cell arrives before the previous F-RM cell was turned around, CI-TA is
overwritten by the new RM cell's CI.
MOTOROLA Chapter 31. ATM Controller and AAL0, AAL1, and AAL5
Freescale Semiconductor, Inc.
2 3 4 5
CI-TA NI-TA —
RM Cell Time Stamp (RCTS)
— CDF
Figure 31-36. ABR Protocol-Specific TCTE
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6 7 8 9 10
ER-TA
CCR-TA
MCR-TA
CP-TA — CI-VC
MCR
UNACK
ACR
—
ICR
CRM
ADTF
ER
ER-BRM
Description
ATM Memory Structure
11 12 13 14 15
—
COUNT
31-63