HD64F3437TF16 Datasheet, PDF (687/752 Pages) Hitachi Semiconductor – 12 V must not be applied to the S-mask model (single-power-supply specification), as this may permanently damage the device.

MDCR—Mode Control Register
• Except H8/3437SF
H'C5
System Control
Bit
7
6
5
4
3
2
1
0
—
—
—
—
—
—
MDS1 MDS0
Initial value
1
1
1
0
0
1
*
*
Read/Write
—
—
—
—
—
—
R
R
Mode Select Bits
Value at mode pins.
Note: * Determined by inputs at pins MD₁ and MD₀.
• H8/3437SF
Bit
7
6
5
4
3
2
1
0
EXPE
—
—
—
—
—
MDS1 MDS0
Initial value
*
1
1
0
0
1
*
*
Read/Write R/W*
—
—
—
—
—
R
R
Mode Select Bits
Value at mode pins.
Expanded Mode Enable
0 Single-chip mode is selected.
1 Expanded mode is selected (writable in boot mode only).
Note: ^* Determined by inputs at pins MD₁ and MD₀.
658