HD404314H View Datasheet(PDF) - Hitachi -> Renesas Electronics

Part Name

Description

Manufacturer

HD404314H

4-bit HMCS400-series microcomputer

Hitachi -> Renesas Electronics 

HD404318 Series

I/O Ports

The MCU has 33 input/output pins (D0–D8, R0–R4, R8) and one input-only pin (RA1). The following

describes the features of the I/O ports.

• The 21 pins consisting of D0–D8, R1, R2, and R8 are all high-voltage I/O pins. RA1 is a high-voltage

input-only pin. These high-voltage pins can be equipped with or without pull-down resistance, as

selected by the mask option.

• All standard output pins are CMOS output pins. However, the R02/SO pin can be programmed for

NMOS open-drain output.

• In stop mode, input/output pins go to the high-impedance state

• All standard input/output pins have pull-up MOS built in, which can be individually turned on or off by

software

Table 5 Control of Standard I/O Pins by Program

MIS3 (bit 3 of MIS)

DCR

PDR

CMOS buffer PMOS

NMOS

Pull-up MOS

Note: — indicates off.

0

1

0

1

0

1

0

1

0

1

0

1

0

1

—

—

—

On

—

—

—

On

—

—

On

—

—

—

On

—

—

—

—

—

—

On

—

On

Data control register (DCR0: $030, DCR3: $033, DCR4: $034)

DCR0, DCR3,

DCR4

Bit

3

2

1

0

Initial value

0

0

0

0

Read/Write

W

W

W

W

Bit name

DCR03, DCR02, DCR01, DCR00,

DCR33, DCR32, DCR31, DCR30,

DCR43, DCR42, DCR41, DCR40

Bits 0 to 3 CMOS Buffer Control

0

CMOS buffer off

(high impedance)

1

CMOS buffer on

Correspondence between ports and DCR bits

Register Bit 3 Bit 2 Bit 1 Bit 0

DCR0

DCR3

DCR4

R03

R02

R01

R00

R33

R32

R31

R30

R43

R42

R41

R40

Figure 17 Data Control Register (DCR)

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