M32C83T datasheet(153/527 Pages) RENESAS

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13. DMACII

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13.3.2 Immediate Data Transfer

The DMAC II transfers immediate data to a desired memory location. A fixed or relocatable address can

be selected as the destination address. Store the immediate data into SADR. To transfer an 8-bit imme-

diate data, write the data in the low-order byte of SADR (high-order byte is ignored).

13.3.3 Calculation Transfer

After two memory data, or an immediate data and memory data are added together, the calculated result

is transferred to a desired memory location. SADR must have one memory location address to be calcu-

lated or immediate data. OADR must have the other memory location address to be calculated. Fixed or

relocatable address can be selected as source and destination addresses when using a memory +

memory calculation transfer. If the transfer source address is relocatable, the operation address also

becomes relocatable. Fixed or relocatable address can be selected as the transfer destination address

when using an immediate data + memory calculation transfer.

13.4 Transfer Modes

In DMAC II, single and burst transfers are available. The BRST bit in MOD selects transfer method, either

the single transfer or burst transfer. COUNT determines how many transfers occur. No transfer occurs

when COUNT is set to "000016". All interrupts are ignored while transfer is in progress.

13.4.1 Single Transfer

For every transfer request factor, the DMAC II transfers one transfer unit of 8-bit or 16-bit data once.

When the source or destination address is relocatable, the DMAC II increments the address, after a

transfer, for the next transfer.

COUNT is decremented every time a transfer occurs. When using the end-of-transfer interrupt, the inter-

rupt is acknowledged when COUNT reaches "0".

13.4.2 Burst Transfer

For every transfer request factor, the DMAC II continuously transfers data the number of times deter-

mined by COUNT. The DMAC II decrements COUNT every time a transfer occurs. The burst transfer

ends when COUNT reaches "0". The end-of-transfer interrupt is acknowledged when the burst transfer

ends if using the end-of-transfer interrupt. All interrupts are ignored while the burst transfer is in progress.

13.4.3 Multiple Transfer

The MULT bit in MOD selects the multiple transfer. When using the multiple transfer, select the memory-

to-memory transfer. One transfer request factor initiates multiple transfers. The CNT2 to CNT0 bits in

MOD selects the number of transfers from "0012" (once) to "1112" (7 times). Do not set the CNT2 to

CNT0 bits to "0002".

The transfer source and destination addresses for each transfer must be allocated alternately to ad-

dresses following MOD and COUNT. When the multiple transfer is selected, the calculation transfer,

burst transfer, end-of-transfer interrupt and chained transfer cannot be used.

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