HD6413008VF25 Datasheet, PDF (102/688 Pages) Renesas Technology Corp – Old Company Name in Catalogs and Other Documents

3. MCU Operating Modes
Modes 1 to 4 are externally expanded modes that enable access to external memory and peripheral
devices and disable access to the on-chip ROM. Modes 1 and 2 support a maximum address space
of 1 Mbyte. Modes 3 and 4 support a maximum address space of 16 Mbytes.
The H8/3008 can be used only in modes 1 to 4. The inputs at the mode pins must select one of
these four modes. The inputs at the mode pins must not be changed during operation. Set the reset
state before changing the inputs at these pins.
3.1.2 Register Configuration
The H8/3008 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'EE011
Mode control register
MDCR
R
H'EE012
System control register SYSCR
R/W
Note: * Lower 20 bits of the address in advanced mode.
Initial Value
Undetermined
H'09
3.2 Mode Control Register (MDCR)
MDCR is an 8-bit read-only register that indicates the current operating mode of the H8/3008.
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
Mode select 2 to 0
Bits indicating the current
operating mode
Note: * Determined by pins MD₂ to MD₀ .
Bits 7 and 6—Reserved: These bits can not be modified and are always read as 1.
Bits 5 to 3—Reserved: These bits can not be modified and are always read as 0.
Bits 2 to 0—Mode Select 2 to 0 (MDS2 to MDS0): These bits indicate the logic levels at pins
MD₂ to MD₀ (the current operating mode). MDS2 to MDS0 correspond to MD₂ to MD₀. MDS2 to
Rev.4.00 Aug. 20, 2007 Page 56 of 638
REJ09B0395-0400