HD6417660 RENESAS [Renesas Technology Corp], HD6417660 Datasheet - Page 359

• Manufacturer Part Number: HD6417660
• Description: Renesas 32-Bit RISC Microcomputer
• Manufacturer: RENESAS [Renesas Technology Corp]

10.4.5
DMA transfer has two types; single address mode transfer and dual address mode transfer, they
depend on the number of bus cycles of access to source and destination. A data transfer timing
depends on the bus mode, which has cycle steal mode and burst mode. The DMAC supports the
transfers shown in table 10.7.
Table 10.7 Supported DMA Transfers
Notes: 1. Dual: Dual address mode
Address Modes:
1. Dual Address Mode
Source
External device with DACK Not available
External memory
Memory-mapped external
device
On-chip peripheral module Not available
X/Y memory, U memory
In the dual address mode, both the transfer source and destination are accessed (selected) by an
address. The source and destination can be located externally or internally.
DMA transfer requires two bus cycles because data is read from the transfer source in a data
read cycle and written to the transfer destination in a data write cycle. At this time, transfer
data is temporarily stored in the DMAC. In the transfer between external memories as shown
in figure 10.5, data is read to the DMAC from one external memory in a data read cycle, and
then that data is written to the other external memory in a write cycle.
2.
3.
DMA Transfer Types
Single: Single address mode
16-byte transfer is not available for on-chip peripheral modules.
Dual, single
Not available
External
Device with
DACK
Dual, single
External
Memory
Dual, single Dual, single Not available Not available
Dual
Dual
Dual
Dual
Dual
Dual
Memory-
Mapped
External
Device
Dual
Dual
Destination
Rev. 1.00, 02/04, page 321 of 804
On-Chip
Peripheral
Module
Dual
Dual
Dual
Dual
X/Y Memory
U Memory
Dual
Dual
Dual
Dual