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2 apc priority table, 3 apc scheduling tables, Apc priority table -63 – Motorola MPC8260 User Manual

Page 843: Apc scheduling tables -63, The apc scheduling table structure -63, Control slot -63, Apc priority table entry -63

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29-63

MPC8260 PowerQUICC II UserÕs Manual

MOTOROLA

Part IV. Communications Processor Module

29.10.4.2 APC Priority Table

Each PHYÕs APC priority table holds pointers to the APC scheduling table of each priority
level. It resides in the dual-port RAM. The priority table can hold up to eight priority levels.
Table 29-30 shows the structure of a priority table entry.

29.10.4.3 APC Scheduling Tables

The APC uses APC scheduling tables (one table for each priority level) to schedule channel
transmission. A scheduling table is divided into time slots, as shown in Figure 29-39. Each
slot is a half-word entry. Note that the APC scheduling tables should be cleared before the
APC unit is enabled.

Figure 29-39. The APC Scheduling Table Structure

Slot N+1 is used as a control slot, as shown in Figure 29-40.

0x0A

LINE_RATE_AB

R

Hword ABR only. The PHY line rate in cells/sec, represented in TM 4.0 ßoating-point

format. User-deÞned.

0xC

REAL_TSTP

Word

Real-time stamp pointer used internally by the APC. Initialize to 0.

0x10

APC_STATE

Word

Used internally by the APC. Initialize to 0.

1

Offset values are to APCP_BASE+PHY#

´ 32. However, in slave mode, the offset is from APCP_BASE regard-

less of the PHY address.

Table 29-30. APC Priority Table Entry

Offset Name

Width

Description

0x00

APC_LEVi_BASE Hword

APC level i base address. Pointer to the first slot in the APC scheduling table for
level i. Should be half-word aligned. User-deÞned.

0x02

APC_LEVi_END

Hword

APC level i end address. Pointer to the last slot in the APC scheduling table for
level i. Should be half-word aligned. User-deÞned.

0x04

APC_LEVi_RPTR Hword

APC level i real-time/service pointers. APC table pointers used internally by the
APC. Initialize both pointers to APC_LEVi_BASE.

0x06

APC_LEVi_SPTR Hword

Bits

0

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

Field

TCTE

000_0000_0000_0000

Figure 29-40. Control Slot

Table 29-29. APC Parameter Table (Continued)

Offset

1

Name

Width

Description

APC_LEVi_BASE

APC_LEVi_END

Half Word Entry

slot 0

slot 1

slot N

Control

Slot