HD6433044 Hitachi Semiconductor, HD6433044 Datasheet - Page 210

• Manufacturer Part Number: HD6433044
• Description: (HD64 Series) Hitachi Single-Chip Microcomputer
• Manufacturer: Hitachi Semiconductor

8.3 Register Descriptions (Full Address Mode)
In full address mode the A and B channels operate together. Full address mode is selected as
indicated in table 8-4.
8.3.1 Memory Address Registers (MAR)
A memory address register (MAR) is a 32-bit readable/writable register. MARA functions as the
source address register of the transfer, and MARB as the destination address register.
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 are always read as 1.
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 8.3.4,
Data Transfer Control Registers (DTCR).
The MARs are not initialized by a reset or in standby mode.
8.3.2 I/O Address Registers (IOAR)
The I/O address registers (IOARs) are not used in full address mode.
Bit
Initial value
Read/Write
31
—
1
30
—
1
29
—
1
MARR
28
—
1
27
—
1
26
—
1
25
—
1
24
—
1
R/W
23
R/W
22
R/W
21
R/W
MARE
20
Source or destination address
R/W
19
R/W
18
196
R/W
17
Undetermined
R/W
16
R/W
15
R/W
14
R/W
13
R/W
MARH
12
R/W
11
R/W
10
R/W
9
R/W
8
R/W
7
R/W
6
R/W
5
R/W
MARL
4
R/W
3
R/W
2
R/W
1
R/W
0