HD64F3048VTF8 Datasheet, PDF (100/903 Pages) Renesas Technology Corp – Hardware Manual Renesas 8-Bit Single-Chip

Section 3 MCU Operating Modes
Modes 5 and 6 are externally expanded modes that enable access to external memory and
peripheral devices and also enable access to the on-chip ROM. Mode 5 supports a maximum
address space of 1 Mbyte. Mode 6 supports a maximum address space of 16 Mbytes.
Mode 7 is a single-chip mode that operates using the on-chip ROM, RAM, and internal I/O
registers, and makes all I/O ports available. Mode 7 supports a 1-Mbyte address space.
The H8/3048B Group can be used only in modes 1 to 7. The inputs at the mode pins must select
one of these seven modes. The inputs at the mode pins must not be changed during operation.
3.1.2 Register Configuration
The H8/3048B Group has a mode control register (MDCR) that indicates the inputs at the mode
pins (MD₂ to MD₀), and a system control register (SYSCR). Table 3.2 summarizes these registers.
Table 3.2 Registers
Address^*
Name
Abbreviation
R/W
H'FFF1
Mode control register
MDCR
R
H'FFF2
System control register
SYSCR
R/W
Note: * The lower 16 bits of the address are indicated.
Initial Value
Undetermined
H'0B
3.2 Mode Control Register (MDCR)
MDCR is an 8-bit read-only register that indicates the current operating mode of the H8/3048B
Group.
Bit
7
6
5
4
3
2
1
0




 MDS2 MDS1 MDS0
Initial value
1
1
0
0
0
*
*
*
Read/Write





R
R
R
Reserved bits
Reserved bits
Mode select 2 to 0
Bits indicating the current
operating mode
Note: * Determined by pins MD₂ to MD₀ .
Rev. 3.00 Sep 27, 2006 page 72 of 872
REJ09B0325-0300