ATM Controller and AAL0, AAL1, and AAL5
MPC8260 PowerQUICC II Family Reference Manual, Rev. 2
Freescale Semiconductor 30-81

30.10.7 UNI Statistics Table

The UNI statistics table, shown in Table30- 41, resides in the dual-port RAM and holds UNI statistics
parameters. UNI_STATT_BASE points to the base address of this table. Each PHY’s own table has a
starting address given by UNI_STATT_BASE+ PHY# ×8.
30.11 ATM Exceptions
The ATM controller interrupt handling involves two principal data structures: FCCEs (FCC event
registers) and circular interrupt queues.
Four priority interrupt queues are available. By programming RCT[INTQ] and TCT[INTQ], the user
determines which queue receives the interrupt. Channel Rx buffer, Rx frame, or Tx buffer events ca n be
masked by clearing interrupt mask bits in RCT and TCT.
After an interrupt request, the host reads FCCE. If FCCE[GINTx] = 1, at least one entry was added to one
of the interrupt queues. After clearing FCCE[GINTx], the host processes the valid interrupt queue entries
and clears each entry’s valid bit. The host follows this procedure until it reaches an entry with V = 0. See
Section 30.11.2, “Interrupt Queue Entry.”
The host controls the number of interrupts sent to the core using a down counter in the interrupt queue’s
parameter table; see Section 30.11.3. For each event sent to an interrupt queue, a counter (that has been
initialized to a threshold number of interrupts) is decremented. When the counter reaches zero, the global
interrupt, FCCE[GINT x], is set.

30.11.1 Interrupt Queues

Interrupt queues are located in external memory. The parameters of each queue are stored in a table. See
Section 30.11.3, “Interrupt Queue Parameter Tables.”
When an interrupt occurs, the CP writes a new entry to the interrupt queue, the V bit is set, and the queue
pointer (INTQ_PTR) is incremented. Once the CP uses an entry with W = 1, it returns to the first entry in
Table30-41. UNI Statistics Table
Offset1
1Offset from UNI_STATT_BASE+PHY# × 8
Name Width Description
0x00 UTOPIAE Hword Counts cells dropped as a result of UTOPIA/ATM protocol violations.
Violations include the following:
1. Parity error
2. HEC error
3. Invalid timing of RxSOC.
If RxClav is asserted for the selected PHY, RxSOC should be asserted the
cycle immediately following the assertion of RXENB. A violation occurs if
RxSOC is not asserted at that time (i.e. is late or is missing).
0x02 MIC_COUNT Hword Counts misinserted cells dropped as a result of address look-up failure.
0x04 CRC10E_COUNT Hword Counts cells dropped as a result of CRC10 failure. AAL5-ABR only.
0x06 Hword Reserved, should be cleared.