HD6413008VF25 Datasheet, PDF (190/688 Pages) Renesas Technology Corp – Old Company Name in Catalogs and Other Documents

7. I/O Ports
7.2 Port 4
7.2.1 Overview
Port 4 is an 8-bit input/output port which also functions as a data bus. It's pin configuration is
shown in figure 7.1. The pin functions differ depending on the operating mode.
In the H8/3008, when the bus width control register (ABWCR) designates areas 0 to 7 all as 8-bit-
access areas, the chip operates in 8-bit bus mode and port 4 is a generic input/output port. When at
least one of areas 0 to 7 is designated as a 16-bit-access area, the chip operates in 16-bit bus mode
and port 4 becomes part of the data bus.
Port 4 has software-programmable built-in pull-up MOS.
Pins in port 4 can drive one TTL load and a 90-pF capacitive load. They can also drive a
darlington transistor pair.
Port 4 pins
Modes 1 to 4
Port 4
P4₇ /D₇
P4₆ /D₆
P4₅ /D₅
P4₄ /D₄
P4₃ /D₃
P4₂ /D₂
P4₁ /D₁
P4₀ /D₀
P4₇ (input/output)/D₇ (input/output)
P4₆ (input/output)/D₆ (input/output)
P4₅ (input/output)/D₅ (input/output)
P4₄ (input/output)/D₄ (input/output)
P4₃ (input/output)/D₃ (input/output)
P4₂ (input/output)/D₂ (input/output)
P4₁ (input/output)/D₁ (input/output)
P4₀ (input/output)/D₀ (input/output)
Figure 7.1 Port 4 Pin Configuration
Rev.4.00 Aug. 20, 2007 Page 144 of 638
REJ09B0395-0400