HD64F3437TF16 Datasheet, PDF (715/752 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.

C.3 Port 3 Block Diagram
HIE Mode 3
Reset
RP3P
Reset
R
Q
D
P3_nPCR
C
WP3P
CS
IOR
External address
write
R
Q
D
P3_nDDR
C
WP3D
P3_n
Modes 1 or 2
CS
IOW
Reset
R
Q
D
P3_nDR
C
WP3
RP3
External address
read
WP3P: Write to P3PCR
WP3D: Write to P3DDR
WP3: Write to port 3
RP3P: Read P3PCR
RP3: Read port 3
n = 0 to 7
Figure C.3 Port 3 Block Diagram
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