Section 7 DMA Controller (DMAC)
Rev. 3.00 Mar. 14, 2006 Page 171 of 804
REJ09B0104-0300
External memory
When the area represented by the lower three bits of DSAR (eight bytes)
is specified as the extended repeat area (SARA4 to SARA0 = B'00011)
Repeat
An interrupt request by extended repeat area
overflow can be generated.
Area specified
by DSAR
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
...
...
Figure 7.15 Example of Extended Repeat Area Operation
When an interrupt by an extended repeat area overflow is used in block transfer mode, the
following should be taken into consideration.
When a transfer is stopped by an interrupt by an extended repeat area overflow, the address
register must be set so that the block size is a power of 2 or the block size boundary is aligned with
the extended repeat area boundary. When an overflow on the extended repeat area occurs during a
transfer of one block, the interrupt by the overflow is suspended and the transfer overruns.
Figure 7.16 shows examples when the extended repeat area function is used in block transfer
mode.
External memory
Area specified
by DSAR
1st block
transfer
2nd 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
request
generated
Block transfer
continued
When the are represented by the lower three bits (eight bytes) of DSAR are specified as the extended
repeat area (SARA4 to SARA0 = 3) and the block size in block transfer mode is specified to 5 (bits 23
to 16 in DTCR = 5).
...
...
Figure 7.16 Example of Extended Repeat Area Function in Block Transfer Mode
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