Operation - Renesas RX100 Series User Manual

RX13T Group
16.4

Operation

The DTC transfers data in accordance with the transfer information. Storage of the transfer information in the RAM area
is required before DTC operation.
When the DTC accepts a transfer request, it reads the DTC vector corresponding to the vector number. Next, the DTC
reads transfer information from the address pointed by the DTC vector, transfers data, and then writes back the transfer
information after the data transfer. Allocating transfer information in the RAM area allows data transfer of arbitrary
number of channels.
There are three transfer modes: normal transfer mode, repeat transfer mode, and block transfer mode.
Set a transfer source address in the SAR register and a transfer destination address in the DAR register. The SAR and
DAR registers are updated after the transfer according to the respective settings (increment, decrement, or fixed).
Table 16.3 lists transfer modes of the DTC.
Table 16.3 Transfer Modes of the DTC
Transfer Mode
Normal transfer mode
1
Repeat transfer mode*
2
Block transfer mode*
Note 1. Set transfer source or transfer destination in the repeat area.
Note 2. Set transfer source or transfer destination in the block area.
Note 3. After data transfer of the specified count, the initial state is restored and the operation is continued (repeated).
Setting the MRB.CHNE bit to 1 allows multiple transfers (chain transfer) on a single transfer request. The setting in
combination with the MRB.CHNS bit enables a chain transfer when the specified number of data transfers is completed.
Figure 16.5 shows the operation flowchart of the DTC. Table 16.4 lists chain transfer conditions.
R01UH0822EJ0100 Rev.1.00
Jul 31, 2019
Data Size Transferred on Single Transfer
Request
1 byte/1 word/1 longword
1 byte/1 word/1 longword
Block size specified in CRAH
(1 to 256 bytes/1 to 256 words/1 to 256
longwords)
16. Data Transfer Controller (DTCb)
Increment/Decrement of
Memory Address
Incremented/decremented by
1, 2, or 4 or address fixed
Incremented/decremented by
1, 2, or 4 or address fixed
Incremented/decremented by
1, 2, or 4 or address fixed
Settable Transfer
Count
1 to 65536
3
1 to 256*
1 to 65536
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