HD6413003RF Datasheet, PDF (198/715 Pages) Renesas Technology Corp – Microcontroller (MCU)

8.2.1 Memory Address Registers (MAR)
A memory address register (MAR) is a 32-bit readable/writable register that specifies a source or
destination address. The transfer direction is determined automatically from the activation source.
An MAR consists of four 8-bit registers designated MARR, MARE, MARH, and MARL. All bits
of MARR are reserved: they cannot be modified and always read 1.
Bit
31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0
Initial value
Undetermined
Read/Write — — — — — — — — R/WR/WR/WR/WR/WR/WR/WR/WR/WR/WR/WR/WR/WR/WR/WR/WR/WR/WR/WR/WR/WR/WR/WR/W
MARR
MARE
MARH
MARL
Source or destination address
An MAR functions as a source or destination address register depending on how the DMAC is
activated: as a destination address register if activation is by a receive-data-full interrupt from the
serial communication interface (SCI), and as a source address register otherwise.
The MAR value is incremented or decremented each time one byte or word is transferred,
automatically updating the source or destination memory address. For details, see section 8.2.4,
Data Transfer Control Registers (DTCR).
The MARs are not initialized by a reset or in standby mode.
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