Datasheet

Section 8 EXDMA Controller
Rev. 3.00 Mar 17, 2006 page 361 of 926
REJ09B0283-0300
mode, the block size must be a power of two, or alternatively, the address register value must be
set so that the end of a block coincides with the end of the repeat area range.
If repeat area overflow occurs while a block is being transferred in block transfer mode, the repeat
interrupt request is held pending until the end of the block, and transfer overrun will occur. Figure
8.10 shows an example in which block transfer mode is used together with the repeat area
function.
External memory
Range of
EDSAR values
First block
transfer
Second block
transfer
H'23FFFE
H'23FFFF
H'240000
H'240001
H'240002
H'240003
H'240004
H'240005
H'240006
H'240007
H'240008
H'240009
H'240000
H'240001
H'240002
H'240003
H'240004
H'240005
H'240006
H'240007
H'240000
H'240001
H'240002
H'240003
H'240004
H'240000
H'240001
H'240005
H'240006
H'240007
:
:
Interrupt
requested
Block transfer
in progress
When lower 3 bits (8-byte area) of EDSAR are designated as repeat area (SARA4 to SARA0 = 3),
and block size of 5 (EDTCR[23–16] = 5) is set in block transfer mode
Figure 8.10 Example of Repeat Area Function Operation in Block Transfer Mode
8.4.7 Registers during DMA Transfer Operation
EXDMAC register values are updated as DMA transfer processing is performed. The updated
values depend on various settings and the transfer status. The following registers and bits are
updated: EDSAR, EDDAR, EDTCR, and bits EDA, BEF, and IRF in EDMDR,
EXDMA Source Address Register (EDSAR): When the EDSAR address is accessed as the
transfer source, after the EDSAR value is output, EDSAR is updated with the address to be