Motorola PowerQUICC II MPC8280 Series Reference Manual page 971

timeslot 7, for example, then timeslots 1 and 6 have CNT=0x7 and BYT=1 and timeslot 7
would be programmed with CNT=0 and BYT=1.
Similarly, the second superchannel in this example sends data beginning with its first
timeslot, timeslot 2. It contains the "first byte" condition of CNT=0 and BYT=1. If the
application required a different timeslot in this superchannel, either timeslot 3 or 4, that
channel could be programmed to have the "first byte" condition instead.
Figure 29-15 shows the SI RAM programming for transparent receiver superchannels
which uses the slot synchronization. This example assumes a timeslot configuration similar
to the transmit example in Figure 29-14. For this receive example, to guarantee that
reception begins on the first timeslots for each superchannel, all timeslots that correspond
to superchannels are programmed as superchannelled timeslots and the first timeslot for
each superchannel is programmed with the "first byte" CNT and BYT conditions.
Note that the receive examples do not include a superchannel table because a superchannel
table is only used on the transmit side. Receive SIRAM entries should always be
programmed using the FIFO number of the managing MCC channel for that superchannel
(the same MCC channel number used in the superchannel table entries corresponding to the
transmit FIFOs for that superchannel).
0
MCC LOOP SUPER
1
1
1
1
1
1
1
1
1
1
First slot of the super channel
2
Regular (not first) slot of the super channel
The super channel BD tables are associated with channels 1 and 2
Figure 29-15. Receiver Super Channel with Slot Synchronization Example
MOTOROLA
Freescale Semiconductor, Inc.
SI RAM
1 2 3–10 11–13
MCSEL
SI RAM Address
0 0 0x0
0 1 0x1
0 1 0x2
0 1 0x2
0 1 0x2
0 0 0x5
0 1 0x1
0 1 0x1
0 0 0x8
Chapter 29. Multi-Channel Controllers (MCCs)
For More Information On This Product,
Go to: www.freescale.com
14 15
CNT BYT LST
1 0 Regular Channel
0x0
1 1 0 Super Channel 1
0x0
1 1 0 Super Channel 2
0x0
2 0 0 Super Channel 2
0x7
2 0 0 Super Channel 2
0x7
1 0 Regular Channel
0x0
2 0 0 Super Channel 1
0x7
0 0 Super Channel 1
2
0x7
1 1 Regular Channel
0x0
Superchannels
29-33