ATM Controller and AAL0, AAL1, and AAL5
MPC8260 PowerQUICC II Family Reference Manual, Rev. 2
Freescale Semiconductor 30-65
30.10.4.2 APC Priority Table

Each PHY’s 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 30-30 shows the

structure of a priority table entry.

30.10.4.3 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 30-39. Each slot is a half-word entry. Note

that the APC scheduling tables should be cleared before the APC unit is enabled.

Figure30-39. The APC Scheduling Table Structure

Slot N+1 is used as a control slot, as shown in Figure30-40.

0x09 CPS_ABR Byte ABR only. Cells per slot represented as a power of two. User-defined. (For
example, if CPS is 1, CPS_ABR = 0x00; if CPS is 8, CPS_ABR = 0x03.)
0x0A LINE_RATE_AB
R
Hword ABR only. The PHY line rate in cells/sec, represented in TM 4.0 floating-point
format. User-defined.
0xC REAL_TSTP Word Real-time stamp pointer used internally by the APC. Should be cleared initially.
0x10 APC_STATE Word Used internally by the APC. Should be cleared initially.
1Offset values are to APCP_BASE+PHY# × 32. However, in slave mode, the offset is from APCP_BASE regardless of
the PHY address.

Table30-30. 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-defined.
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-defined.
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

Table30-29. APC Parameter Table (continued)

Offset1Name Width Description
APC_LEVi_BASE
APC_LEVi_END
Half Word Entry
slot 0 slot 1 slot N Control
Slot