HD6432621 Hitachi, HD6432621 Datasheet - Page 118

• Manufacturer Part Number: HD6432621
• Description: (HD64F262x Series) 16-Bit Microcomputer
• Manufacturer: Hitachi

The H8S/2626 Series and H8S/2623 Series 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/2626 Series and H8S/2623 Series have 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/2626 Series or H8S/2623 Series chip. Table 3-2 summarizes these
registers.
Table 3-2
Name
Mode control register
System control register
Pin function control register
Note: * Lower 16 bits of the address.
3.2
3.2.1
MDCR is an 8-bit register that indicates the current operating mode of the H8S/2626 Series or
H8S/2623 Series chip.
Bit 7—Reserved: Only 1 should be written to this bit.
Bits 6 to 3—Reserved: These bits are always read as 0 and cannot be modified.
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.
MDS2 to MDS0 are read-only bits-they cannot be written to. The mode pin (MD2 to MD0) input
levels are latched into these bits when MDCR is read. These latches are canceled by a reset.
74
Bit
Initial value
R/W
Note: * Determined by pins MD2 to MD0.
Register Configuration
Register Descriptions
Mode Control Register (MDCR)
MCU Registers
:
:
:
R/W
—
7
1
—
—
6
0
Abbreviation
MDCR
SYSCR
PFCR
—
—
5
0
—
—
4
0
R/W
R/W
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