SH7058 Datasheet, PDF (224/1130 Pages) Renesas Technology Corp – Renesas SuperHTM RISC engine

10.3.5 Dual Address Mode
Dual address mode is used for access of both the transfer source and destination by address.
Transfer source and destination can be accessed either internally or externally. Dual address mode
is subdivided into two other modes: direct address transfer mode and indirect address transfer
mode.
Direct Address Transfer Mode: Data is read from the transfer source during the data read cycle,
and written to the transfer destination during the write cycle, so transfer is conducted in two bus
cycles. At this time, the transfer data is temporarily stored in the DMAC. With the kind of external
memory transfer shown in figure 10.3, data is read from one of the memories by the DMAC
during a read cycle, then written to the other external memory during the subsequent write cycle.
Figure 10.4 shows the timing for this operation.
Rev. 3.0, 09/04, page 183 of 1086