Receive Connection Table (Rct) - Freescale Semiconductor MPC850 User Manual

Receive and Transmit Connection Tables (RCTs and TCTs)
CTBASE
RCT0 (Global raw cell queue)
(Located in the
Parameter RAM)
Connection Tables for Internal Channels
Figure 37-7. Connection Tables in Dual-port RAM and External Memory
Note that some CT space is reserved. RCT0 is reserved for the global raw cell queue. (TCT0
is still available to the user.) In extended channel mode, an additional CT pair immediately
above the CTBASE pointer is reserved for internal use.

37.2.1 Receive Connection Table (RCT)

Each receive connection table (RCT) holds parameters (channel configuration, pointers,
status flags, and temporary data) for a single ATM receive channel. Figure 37-8 shows the
RCT structure.
0 1
CT_Offset + 0 FHNT —
CT_Offset + 2
CT_Offset + 4
CT_Offset + 6
CT_Offset + 8
CT_Offset + A
CT_Offset + C
CT_Offset + E
CT_Offset + 10
CT_Offset + 12
CT_Offset + 14
CT_Offset + 16
to
CT_Offset + 1F
Dual-port RAM
Reserved in
RCT (Internal Use)
Extended Channel
TCT (Internal Use)
Mode
TCT0
RCT1
TCT1
RCT2
TCT2
RCT3
TCT3
RCT31
TCT31
2 3 4 5
— — — —
Figure 37-8. Receive Connection Table (RCT)
MPC850 Family User's Manual
ECTBASE
(Located in the
Parameter RAM)
Connection Tables for External Channels
6 7 8 9 10
— —
HEC CLP CNG
RBALEN
RCRC
RB_PTR
RTMLEN
RBD_PTR
RBASE
TSTAMP
IMASK
—
External Memory
32 x 64 Bytes
of User Space
RCT32
TCT32
RCT33
TCT33
RCT34
TCT34
RCT65534
TCT65534
11 12 13 14
INF CNGI CDIS AAL
15