h8s-2646 Renesas Electronics Corporation., h8s-2646 Datasheet - Page 104

• Manufacturer Part Number: h8s-2646
• Description: Renesas 16-bit Single-chip Microcomputer H8s Family/h8s/2600 Series
• Manufacturer: Renesas Electronics Corporation.

Section 3 MCU Operating Modes
Note that the functions of each pin depend on the operating mode.
The H8S/2646 Group can be used only in modes 4 to 7. This means that the mode pins must be set
to select one of these modes. Do not change the inputs at the mode pins during operation.
3.1.2
The H8S/2646 Group has a mode control register (MDCR) that indicates the inputs at the mode
pins (MD2 to MD0), and a system control register (SYSCR) that controls the operation of the
H8S/2646 Group. Table 3.2 summarizes these registers.
Table 3.2
Note: * Lower 16 bits of the address.
3.2
3.2.1
MDCR is an 8-bit read-only register that indicates the current operating mode of the H8S/2646
Group.
Bit 7—Reserved: Cannot be written to.
Bits 6 to 3—Reserved: These bits are always read as 0 and cannot be written to.
Bits 2 to 0—Mode Select 2 to 0 (MDS2 to MDS0): These bits indicate the input levels at pins
MD2 to MD0 (the current operating mode). Bits MDS2 to MDS0 correspond to MD2 to MD0.
Rev. 5.00 Sep 22, 2005 page 78 of 1136
REJ09B0257-0500
Name
Mode control register
System control register
Pin function control register
Bit
Initial value
R/W
Note: * Determined by pins MD2 to MD0.
Register Configuration
Register Descriptions
Mode Control Register (MDCR)
MCU Registers
:
:
:
—
—
7
1
—
—
6
0
MDCR
Abbreviation
SYSCR
PFCR
—
—
5
0
—
—
4
0
R/W
R
R/W
R/W
—
—
3
0
Initial Value
Undetermined
H'01
H'0D/H'00
MDS2
—*
R
2
MDS1
—*
R
1
Address *
H'FDE7
H'FDE5
H'FDEB
MDS0
—*
R
0