SH7751 Datasheet, PDF (596/1224 Pages) Renesas Technology Corp – 32-Bit RISC Microcomputer

14. Direct Memory Access Controller (DMAC)
• The following kinds of DMAC transfer activation requests are provided
⎯ External request
(1) Normal DMA mode
Two DREQ pins. Low level detection or falling edge detection can be specified.
External requests can only be accepted on channel 0 and channel 1.
(2) On-demand data transfer mode (DDT mode)
The SH7551 performs interfacing between an external device and the DMAC using the
DBREQ, BAVL, TR, TDACK, ID [1:0], and D[31:0] pins. The SH7551R performs
interfacing between an external device and the DMAC using the DBREQ, BAVL, TR,
TDACK, ID [2:0], and D[31:0] pins. External requests can be accepted on all eight
channels.
Channel 0 does not have a request queue, but channels 1 to 3 in the SH7751 and
channels 1 to 7 in the SH7751R each have four request queues.
⎯ On-chip peripheral modules request
Transfer requests from the SCI, SCF, and TMU. These can be accepted on all channels.
⎯ Auto-request
A transfer request is generated automatically within the DMAC.
• Channel functions: Transfer modes that can be set are different for each channel.
(1) Normal DMA mode
• Channel 0: Single or dual address mode. External requests are accepted.
• Channel 1: Single or dual address mode. External requests are accepted.
• Channel 2: Dual address mode only
• Channel 3: Dual address mode only
• Channel 4 (SH7751R only): Dual address mode only
• Channel 5 (SH7751R only): Dual address mode only
• Channel 6 (SH7751R only): Dual address mode only
• Channel 7 (SH7751R only): Dual address mode only
(2) DDT mode
• Channel 0: Single or dual address mode. External requests are accepted.
• Channel 1: Single or dual address mode. External requests are accepted.
• Channel 2: Single or dual address mode. External requests are accepted.
• Channel 3: Single or dual address mode. External requests are accepted.
• Channel 4 (SH7751R only): Single or dual address mode. External requests are
accepted.
• Channel 5 (SH7751R only): Single or dual address mode. External requests are
accepted.
Rev.4.00 Oct. 10, 2008 Page 498 of 1122
REJ09B0370-0400