Section 11 Direct Memory Access Controller (DMAC)
Rev. 2.00 Mar 09, 2006 page 461 of 906
REJ09B0292-0200
Section 11 Direct Memory Access Controller (DMAC)
11.1
Overview
A two-channel direct memory access controller (DMAC) is included on-chip. The DMAC can be
used in place of the CPU to perform high-speed data transfers between external devices equipped
with DACK (transfer request acknowledge signal), external memories, on-chip memory, and
memory-mapped external devices. Using the DMAC reduces the burden on the CPU and increases
the operating efficiency of the chip as a whole.
11.1.1
Features
The DMAC has the following features:
•
Two channels
•
Address space: Architecturally 4 Gbytes
•
Choice of data transfer unit: Byte, word (2-byte), longword (4-byte) or 16-byte unit (In a 16-
byte transfer, four longword reads are executed, followed by four longword writes.)
•
Maximum of 16,777,216 (16M) transfers
•
In the event of a cache hit, CPU instruction processing and DMA operation can be executed in
parallel
•
Single address mode transfers: Either the transfer source or transfer destination (peripheral
device) is accessed by a DACK signal (selectable) while the other is accessed by address. One
transfer unit of data is transferred in one bus cycle.
Possible transfer devices: External devices with DACK and memory-mapped external devices
(including external memory)
•
Dual address mode transfer: Both the transfer source and transfer destination are accessed by
address. One transfer unit of data is transferred in two bus cycles.
Possible transfer devices:
Two external memories
External memory and memory-mapped external device
Two memory-mapped external devices
External memory and on-chip peripheral module (excluding DMAC, BSC, UBC, cache-
memory, E-DMAC, and EtherC)
Memory-mapped external device and on-chip peripheral module (excluding DMAC, BSC,
UBC, cache-memory, E-DMAC, and EtherC)
Summary of Contents for SH7616
Page 10: ...Rev 2 00 Mar 09 2006 page x of xxvi ...
Page 132: ...Section 2 CPU Rev 2 00 Mar 09 2006 page 106 of 906 REJ09B0292 0200 ...
Page 568: ...Section 12 16 Bit Free Running Timer FRT Rev 2 00 Mar 09 2006 page 542 of 906 REJ09B0292 0200 ...
Page 582: ...Section 13 Watchdog Timer WDT Rev 2 00 Mar 09 2006 page 556 of 906 REJ09B0292 0200 ...
Page 706: ...Section 16 Serial I O SIO Rev 2 00 Mar 09 2006 page 680 of 906 REJ09B0292 0200 ...
Page 820: ...Section 19 Pin Function Controller PFC Rev 2 00 Mar 09 2006 page 794 of 906 REJ09B0292 0200 ...
Page 932: ...Appendix D Package Dimensions Rev 2 00 Mar 09 2006 page 906 of 906 REJ09B0292 0200 ...
Page 935: ...SH7616 Hardware Manual ...