HD64F3437TF16 Datasheet, PDF (739/752 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.

Wait input enable
Modes 1 or 2
Reset
Q
R
D
P9₇DDR
C
WP9D
Reset
R
P9₇
QD
P9₇DR
C
WP9
RP9
WAIT input
WP9D: Write to P9DDR
WP9: Write to port 9
RP9: Read port 9
Note: For a block diagram when the SDA pin function is selected, see section 13, I²C Bus Interface.
Figure C.9 (f) Port 9 Block Diagram (Pin P9₇)
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