Freescale Semiconductor MPC8260 - Manual (Page 1155)

Inverse Multiplexing for ATM (IMA)
MPC8260 PowerQUICC II Family Reference Manual, Rev. 2
Freescale Semiconductor 33-53
33.4.8.2.2 Programming the FCC Parameter Shadow
All of the user-defined or user-initialized FCC parameters of the FCC should be copied from the FCC
parameter page to the shadow page. The following parameters are exceptions:
• RCELL_TMP_BASE of the shadow page must differ from RCELL_TMP_BASE of the FCC
parameter page. This RCELL_TMP_BASE must point to a separate temporary cell storage area
similar to that reserved on the FCC parameter page.
• Either:
— (1) INTT_BASE of the shadow page must differ from the INTT_BASE of the FCC parameter
page, and along with it separate interrupt parameters and queues.
— OR (2) INTT_BASE of the shadow page and FCC parameter page may be the same and
therefore share common structures, but (a) receive interrupts for the data channels associated
with non-IMA links, data channels associated with non-IDCR IMA links, and ICP channels for
group-unassigned IMA links must be directed to one dedicated interrupt queue, and (b) receive
interrupts for the data channels of group-assigned IMA links using IDCR must be directed to
another dedicated interrupt queue.
• COMM_INFO on the shadow page is unused. ATM commands issued will use the COMM_INFO
fields on the FCC parameter page.
• INT_RCT_BASE and EXT_RCT_BASE should be the same for both the shadow page and the
FCC parameter page. However, (a) received data from data channels associated with non-IMA
links, received data from data channels associated with non-IDCR IMA links, and received ICP
cells from group-unassigned IMA links, and (b) received data and ICP cells from group-assigned
IMA links using IDCR must never target the same receive queues. This would not normally be
done anyway; however, if it was done, it would result in erratic operation.
33.4.8.2.3 On-the-Fly Changes of FCC Parameters
In general, the FCC parameters should not require changes when the FCC is operating. In the event that
on-the-fly changes of FCC parameters is performed, those changes should be made one-by-one first in the
parameters of the shadow area, followed by the same change in the FCC parameter area.
Table 33-24. Unavailable Features when DREQ x used as IDCR Master Clock
IDCR Master Clock DPRAM Page PowerQUICC II Features Not Available
DREQ1 8 MCC1, SMC1, and IDMA1 are unavailable.
DREQ2 9 MCC2, SMC2, and IDMA2
DREQ3 10 SPI and IDMA3
DREQ4 11 RISC Timers, Microcode Rev Num, Random Number Generator
function and IDMA4