SH7080 Datasheet, PDF(247/1644 Page) Renesas Technology Corp – 32-Bit RISC Microcomputer SuperH™ RISC engine Family

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SH7080 Datasheet, PDF (247/1644 Pages) Renesas Technology Corp – 32-Bit RISC Microcomputer SuperH™ RISC engine Family

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Section 8 Data Transfer Controller (DTC)

8.5 Operation

There are three transfer modes: normal, repeat, and block transfer modes. Since transfer

information is in the data area, it is possible to transfer data over any required number of channels.

When activated, the DTC reads transfer information stored in the data are and transfers data

according to the transfer information. After the data transfer is complete, it writes updated transfer

information back to the data area.

The DTC specifies the source address and destination address in SAR and DAR, respectively.

After a transfer, SAR and DAR are incremented, decremented, or fixed independently.

Table 8.3 shows the DTC transfer modes.

Table 8.3 DTC Transfer Modes

Transfer Size of Data Transferred at One Memory Address Increment or

Mode Transfer Request

Decrement

Transfer

Count

Normal

Repeat*1

Block*2

1 byte/word/longword

1 byte/word/longword

Block size specified by CRAH (1

to 256 bytes/words/longwords)

Incremented/decremented by 1, 2, or

4, or fixed

Incremented/decremented by 1, 2, or

4, or fixed

Incremented/decremented by 1, 2, or

4, or fixed

1 to 65536

1 to 256*3

1 to 65536*4

Notes: 1. Either source or destination is specified to repeat area.

2. Either source or destination is specified to block area.

3. After transfer of the specified transfer count, initial state is recovered to continue the

operation.

4. Number of transfers of the specified block size of data.

Setting the CHNE bit in MRB to 1 makes it possible to perform a number of transfers with a

single activation (chain transfer). Setting the CHNS bit in MRB to 1 can also be made to have

chain transfer performed only when the transfer counter value is 0.

Figure 8.4 shows a flowchart of DTC operation, and table 8.4 summarizes the conditions for DTC

transfers including chain transfer (combinations for performing the second and third transfers are

omitted).

Rev. 3.00 May 17, 2007 Page 189 of 1582

REJ09B0181-0300

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