![](http://datasheet.mmic.net.cn/280000/HF234BT100D3201_datasheet_16070274/HF234BT100D3201_92.png)
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3.1.3
Register Configuration
The H8S/2345 Series has a mode control register (MDCR) that indicates the inputs at the mode
pins (MD
2
to MD
0
), and a system control register (SYSCR) and a system control register 2
(SYSCR2)*
2
that control the operation of the H8S/2345 Series. Table 3.3 summarizes these
registers.
Table 3.3
MCU Registers
Name
Abbreviation
R/W
Initial Value
Address
*
1
Mode control register
MDCR
R
Undetermined
H'FF3B
System control register
SYSCR
R/W
H'01
H'FF39
System control register 2
*
2
Notes: 1. Lower 16 bits of the address.
2. The SYSCR2 register can only be used in the F-ZTAT version. In the ZTAT, mask
ROM, and ROMless versions, this register cannot be written to and will return an
undefined value of read.
SYSCR2
R/W
H'00
H'FF42
3.2
Register Descriptions
3.2.1
Mode Control Register (MDCR)
7
—
1
—
6
—
0
—
5
—
0
—
4
—
0
—
3
—
0
—
0
MDS0
—
*
R
2
MDS2
—
*
R
1
MDS1
—
*
R
Note:
*
Determined by pins MD
2
to MD
0
.
Bit
Initial value
R/W
:
:
:
MDCR is an 8-bit read-only register that indicates the current operating mode of the H8S/2345
Series.
Bit 7—Reserved:
Read-only bit, always read as 1.
Bits 6 to 3—Reserved:
Read-only bits, always read as 0.
Bits 2 to 0—Mode Select 2 to 0 (MDS2 to MDS0):
These bits indicate the input levels at pins
MD
2
to MD
0
(the current operating mode). Bits MDS2 to MDS0 correspond to MD
2
to MD
0
.
MDS2 to MDS0 are read-only bits-they cannot be written to. The mode pin (MD
2
to MD
0
) input
levels are latched into these bits when MDCR is read. These latches are canceled by a power-on
reset, but are retained after a manual reset.