HD6433937 Datasheet, PDF (166/521 Pages) Hitachi Semiconductor – Hardware Manual

8.5 Port 4*
Note: * P4₃/IRQ₀, only, is a chip internal input port.
8.5.1 Overview
Port 4 is a 3-bit I/O port and 1-bit input internal port, configured as shown in figure 8-4. P4₃/IRQ₀
is an internal function that performs interfacing to the FLEX™ decoder incorporated in the chip.
It cannot be connected to an IC outside the chip.
Port 4
P4₃ /IRQ₀
P4₂ /TXD₃₂
P4₁ /RXD₃₂
P4₀ /SCK₃₂
READY
FLEX™
decoder
Note:
: Connected inside the chip (P4₃ only).
Figure 8-4 Port 4 Pin Configuration
8.5.2 Register Configuration and Description
Table 8-11 shows the port 4 register configuration.
Table 8-11 Port 4 Registers
Name
Port data register 4
Port control register 4
Abbrev.
R/W
PDR4
R/W
PCR4
W
Initial Value
H'F8
H'F8
Address
H'FFD7
H'FFE7
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