HD64F3048F16 Datasheet, PDF (234/903 Pages) Renesas Technology Corp – Old Company Name in Catalogs and Other Documents

Section 8 DMA Controller
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.
8.2.2 I/O Address Registers (IOAR)
An I/O address register (IOAR) is an 8-bit readable/writable register that specifies a source or
destination address. The IOAR value is the lower 8 bits of the address. The upper 16 address bits
are all 1 (H'FFFF).
Bit
7
6
5
4
3
2
1
0
Initial value
Read/Write
Undetermined
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
Source or destination address
An IOAR functions as a source or destination address register depending on how the DMAC is
activated: as a source address register if activation is by a receive-data-full interrupt from the SCI
(channel 0), and as a destination address register otherwise.
The IOAR value is held fixed. It is not incremented or decremented when a transfer is executed.
The IOARs are not initialized by a reset or in standby mode.
8.2.3 Execute Transfer Count Registers (ETCR)
An execute transfer count register (ETCR) is a 16-bit readable/writable register that specifies the
number of transfers to be executed. These registers function in one way in I/O mode and idle
mode, and another way in repeat mode.
Rev. 3.00 Sep 27, 2006 page 206 of 872
REJ09B0325-0300