Addressing Mode - Fujitsu FR60 Hardware Manual
32-bit microcontroller
mb91301 series
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Also See for FR60:
- Hardware manual (664 pages) ,
- User manual (104 pages) ,
- User manual (1038 pages)
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CHAPTER 14 DMA CONTROLLER (DMAC)
14.3.4 Addressing Mode
Specify the transfer destination/transfer source address independently for each
transfer channel.
■ Address Register Specifications
The following two methods are provided to specify an address register. The method specified
depends on the transfer sequence.
•
In 2-cycle transfer mode, set the transfer source address in the transfer source address
setting register (DMASA) and the transfer destination address in the transfer destination
address setting register (DMADA).
•
In fly-by transfer mode, specify the memory address in the transfer destination address
setting register (DMADA). In this case, the value in the transfer source address setting
register (DMASA) is ignored.
■ Features of the Address Register
This register has the maximum 32-bit length. With 32-bit length, all space in the memory map
can be accessed.
■ Function of the Address Register
•
The address register is read in each access operation and the read value is sent to the
address bus.
•
At the same time, the address for the next access is calculated by the address counter and
the address register is updated using the calculated address.
•
For address calculation, increment or decrement is selected independently for each channel,
transfer destination, and transfer source. The address increment/decrement width is
specified by the address count size register (SASZ/DASZ of DMACB).
•
If reloading is not enabled, the address resulting from the address calculation of the last
address remains in the address register when the transfer ends.
•
If reloading is enabled, the initial value of the address is reloaded.
Notes:
• If an overflow or underflow occurs as a result of 32-bit length full address calculation, an address
error is detected and transfer on the relevant channel is stopped. Refer to the description for the
items related to the end code.
• Do not set any of the DMAC's registers as the address register.
• For demand transfer, be sure to set an address in an external area for the transfer source,
transfer destination, or both.
• Do not let the DMAC transfer data to any of the DMAC's registers.
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