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CHAPTER 16 DMA CONTROLLER (DMAC)
16.3.5
Data Types
Select the data length (data width) transferred in one transfer operation from the
following:
• Byte
• Halfword
• Word
■ Data Length (Data Width)
Since the word boundary specification is also observed in DMA transfer, different low-order bits
are ignored if an address with a different data length is specified for the transfer destination/
transfer source address.
•
Byte:
•
Halfword:The actual access address has 2-byte length starting with 0 as the lowest-order bit.
•
Word:
If the lowest-order bits in the transfer source address and transfer destination address are
different, the addresses as set are output on the internal address bus. However, each transfer
target on the bus is accessed after the addresses are corrected according to the above rules.
354
The actual access address and the addressing match.
The actual access address has a 4-byte length starting with 00 as the lowest-order
bits.
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