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Renesas SH7781 User Manual

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14. Direct Memory Access Controller (DMAC)

Rev.1.00 Jan. 10, 2008 Page 707 of 1658

REJ09B0261-0100

CH1

> CH2 > CH3 > CH4 > CH5 > CH0

CH0

> CH1 > CH2 > CH3 > CH4 > CH5

CH2

> CH3 > CH4 > CH5 > CH0 > CH1

CH0

> CH1 > CH2 > CH3 > CH4 > CH5

CH0

> CH1 > CH2 > CH3 > CH4 > CH5

CH0

> CH1 > CH2 > CH3 > CH4 > CH5

CH0

> CH1 > CH2 > CH3 > CH4 > CH5

CH3

> CH4 > CH5 > CH0 > CH1 > CH2

CH0

> CH1 > CH2 > CH3 > CH4 > CH5

(1) When channel 0 transfers

Initial priority order

Initial priority order

Initial priority order

Initial priority order

Priority order
after transfer

Priority order does not change.

Channel 2 becomes bottom
priority.
The priority of channels 0 and 1,
which were higher than channel 2,
are also shifted. If immediately
after there is a request to transfer
channel 5 only, channel 5 becomes
bottom priority and the priority of
channels 3 and 4, which were
higher than channel 5, are also
shifted.

Channel 1 becomes bottom
priority.
The priority of channel 0, which
was higher than channel 1, is also
shifted.

Channel 0 becomes bottom
priority

Priority order
after transfer

Priority order
after transfer

Priority order
after transfer

Post-transfer priority order
when there is an
immediate transfer
request to channel 5 only

(2) When channel 1 transfers

(3) When channel 2 transfers

(4) When channel 5 transfers

Figure 14.2 Round-Robin Mode (Example of Channels 0 to 5)