HD64F3437TF16 Datasheet, PDF (145/752 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.

7.4 Port 3
7.4.1 Overview
Port 3 is an 8-bit input/output port that is multiplexed with the data bus and host interface data bus.
Figure 7.9 shows the pin configuration of port 3. The pin functions differ depending on the
operating mode.
Port 3 has built-in, programmable MOS input pull-up transistors that can be used in mode 3.
Pins in port 3 can drive one TTL load and a 90-pF capacitive load. They can also drive a
darlington transistor.
Port 3
116
Port 3 pins
P3₇/D₇/HDB₇
P3₆/D₆/HDB₆
P3₅/D₅/HDB₅
P3₄/D₄/HDB₄
P3₃/D₃/HDB₃
P3₂/D₂/HDB₂
P3₁/D₁/HDB₁
P3₀/D₀/HDB₀
Pin configuration in mode 1
(expanded mode with on-chip
ROM disabled) and mode 2
(expanded mode with on-chip
ROM enabled)
D₇ (input/output)
D₆ (input/output)
D₅ (input/output)
D₄ (input/output)
D₃ (input/output)
D₂ (input/output)
D₁ (input/output)
D₀ (input/output)
Pin configuration in mode 3 (single-chip mode)
Master mode
P3₇ (input/output)
P3₆ (input/output)
P3₅ (input/output)
P3₄ (input/output)
P3₃ (input/output)
P3₂ (input/output)
P3₁ (input/output)
P3₀ (input/output)
Slave mode
HDB₇ (input/output)
HDB₆ (input/output)
HDB₅ (input/output)
HDB₄ (input/output)
HDB₃ (input/output)
HDB₂ (input/output)
HDB₁ (input/output)
HDB₀ (input/output)
Figure 7.9 Port 3 Pin Configuration