HD6473032F16 Datasheet, PDF (90/847 Pages) Renesas Technology Corp – Hardware Manual Renesas 16-Bit Single-Chip Microcomputer H8 Family/H8/300H Series

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 H8/3052BF 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 H8/3052BF 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 H8/3052BF.
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
Note: * Determined by pins MD₂ to MD₀ .
Bits 7 and 6—Reserved: Read-only bits, always read as 1.
Bits 5 to 3—Reserved: Read-only bits, always read as 0.
Rev. 3.00 Mar 21, 2006 page 60 of 814
REJ09B0302-0300
Mode select 2 to 0
Bits indicating the current
operating mode