Section 7 DMA Controller (DMAC)
Rev. 3.00 Mar. 14, 2006 Page 174 of 804
REJ09B0104-0300
(2)
XY Conversion Using Offset
Figure 7.19 shows the XY conversion using the offset addition in repeat transfer mode.
Data 1
Data 2
Data 3
Data 4
Data 5
Data 11
Data 12
Data 16
Data 16
Data 15
Data 14
Data 13
Data 10
Data 9
Data 8
Data 7
Data 6
Data 1
Data 5
Data 9
Data 13
Data 2
Data 11
Data 15
Data 12
Data 8
Data 4
Data 7
Data 3
Data 14
Data 10
Data 6
1st transfer
1st transfer
2nd transfer
2nd transfer
3rd transfer
3rd transfer
4th transfer
1st transfer
2nd transfer
3rd transfer
4th transfer
Data 1
Data 2
Data 3
Data 4
Data 15
Data 5
Data 11
Data 12
Data 16
Data 14
Data 13
Data 10
Data 9
Data 8
Data 7
Data 6
Data 1
Data 2
Data 3
Data 4
Data 15
Data 5
Data 11
Data 12
Data 16
Data 14
Data 13
Data 10
Data 9
Data 8
Data 7
Data 6
Data 1
Data 2
Data 3
Data 4
Data 15
Data 5
Data 11
Data 12
Data 16
Data 14
Data 13
Data 10
Data 9
Data 8
Data 7
Data 6
Data 1
Data 5
Data 9
Data 13
Data 12
Data 2
Data 11
Data 15
Data 16
Data 8
Data 4
Data 7
Data 3
Data 14
Data 10
Data 6
Transfer
Transfer
Interrupt
request
generated
Interrupt
request
generated
Address
initialized
Interrupt
request
generated
Address
initialized
Transfer source
addresses
changed by CPU
Transfer source
addresses
changed by CPU
Offset
Offset
Offset
Figure 7.19 XY Conversion Operation Using Offset Addition in Repeat Transfer Mode
In figure 7.19, the source address side is specified to the repeat area by DACR and the offset
addition is selected. The offset value is set to 4
×
data access size (when the data access size is
longword, H'00000010 is set in DOFR, as an example). The repeat size is set to 4
×
data access
size (when the data access size is longword, the repeat size is set to 4
×
4 = 16 bytes, as an
example). The increment or decrement by 1, 2, or 4 is specified as the transfer destination address.
A repeat size end interrupt is requested when the repeat size of transfers is completed.
When a transfer starts, the transfer source address is added to the offset every time data is
transferred. The transfer data is written to the destination continuous addresses. When data 4 is
transferred meaning that the repeat size of transfers is completed, the transfer source address
returns to the transfer start address (address of data 1 on the transfer source) and a repeat size end
interrupt is requested. While this interrupt stops the transfer temporarily, the contents of DSAR are
written to the address of data 5 by the CPU (when the data access size is longword, write the data
1 a 4). When the DTE bit in DMDR is set to 1, the transfer is resumed from the state when
the transfer is stopped. Accordingly, operations are repeated and the transfer source data is
transposed to the destination area (XY conversion).
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