Multi-Channel Controllers (MCCs)
MPC8260 PowerQUICC II Family Reference Manual, Rev. 2
28-50 Freescale Semiconductor
If multiple synchronized TDMs are used (as an example 8 T1 with common clock/sync) it is recommended
to start the TDMs out of phase relative to each other, in order to spread out CPM and bus utilization. This
avoids CPM and bus activity peaks when all the channels would require CPM attention and possibly have
to transfer data to/from the memory simultaneously.
When MCC FIFO activity starts, the MCC begins to consume CPM bandwidth immediately upon enabling
a TDM which has MCC-related SIRAM programming. This is regardless of whether a channel is stopped
or has the “start condition” programmed in the RSTATE and TSTATE channel-specific parameters. If a
user wishes to spread out CPM and bus utilization for the MCC channels on a particular TDM, those
channels must be dynamically added to the SIRAM programming in an evenly distributed fashion over
multiple TDM frames.