SH7727 Datasheet, PDF (475/1109 Pages) Renesas Technology Corp – Renesas 32-Bit RISC Microcomputer SuperH RISC engine Family/SH7700 Series

Section 14 Direct Memory Access Controller (DMAC)
(1) When channel 0 transfers
Initial priority order _{CH0 > CH1 > CH2 > CH3}
Channel 0 becomes bottom
priority
Priority order
afrer transfer
CH1 > CH2 > CH3 > CH0
(2) When channel 1 transfers
Initial priority order
Priority order
afrer transfer
CH0 > CH1 > CH2 > CH3
CH2 > CH3 > CH0 > CH1
Channel 0 becomes bottom
priority.
The priority of channel 0, which
was higher than channel 3, is also
shifted.
(3) When channel 2 transfers
Initial priority order CH0 > CH1 > CH2 > CH3
Channel 2 becomes bottom
priority.
The priority of channels 0 and 1,
which were higher than channel 2,
are also shifted. If immediately
Priority order
afrer transfer
CH3 > CH0 > CH1 > CH2 ^{after there is a request to transfer}
channel 1 only, channel 1 becomes
bottom priority and the priority of
channels 0 and 3, which were
Post-transfer priority order
higher than channel 1, are also
when there is an
immediate transfer
CH2 > CH3 > CH0 > CH1 ^shifted.
request to channel 1 only
(4) When channel 3 transfers
Priority order
afrer transfer
Priority order
afrer transfer
CH0 > CH1 > CH2 > CH3
Initial priority order
CH0 > CH1 > CH2 > CH3
Figure 14.3 Operation in Round-Robin Mode
Rev. 5.00 Dec 12, 2005 page 403 of 1034
REJ09B0254-0500