Transfer on channel 0
Channel 0 is given the lowest
priority.
CH0 > CH1 > CH2 > CH3
Initial priority order
CH1 > CH2 > CH3 > CH0
Priority order after transfer
Transfer on channel 1
When channel 1 is given the
lowest priority, the priority of
channel 0, which was higher
than channel 1, is also
Initial priority order
CH0 > CH1 > CH2 > CH3
shifted simultaneously.
CH2 > CH3 > CH0 > CH1
Priority order after transfer
Transfer on channel 2
When channel 2 is given the
lowest priority, the priorities of
channels 0 and 1, which were
higher than channel 2, are
also shifted simultaneously. If
there is a transfer request for
channel 1 only immediately
afterward, channel 1 is given
the lowest priority and the
priorities of channels 3 and 0
are simultaneously shifted
down.
Initial priority order
CH0 > CH1 > CH2 > CH3
Priority order after transfer
CH3 > CH0 > CH1 > CH2
CH2 > CH3 > CH0 > CH1
Priority after transfer due to
issuance of a transfer request
for channel 1 only.
Transfer on channel 3
No change in priority order
Initial priority order
CH0 > CH1 > CH2 > CH3
CH0 > CH1 > CH2 > CH3
Priority order after transfer
Figure 14.3 Round Robin Mode
Figure 14.4 shows the changes in priority levels when transfer requests are issued simultaneously
for channels 0 and 3, and channel 1 receives a transfer request during a transfer on channel 0. The
operation of the DMAC in this case is as follows.
Rev. 6.0, 07/02, page 516 of 986
RENESAS [ RENESAS TECHNOLOGY CORP ]
