HD6433713 datasheet(214/324 Pages) RENESAS

214 / 324 page

Section 12 VFD Controller/Driver

12.1 Overview

The H8/3714 Series is equipped with an on-chip vacuum fluorescent display (VFD) controller/

driver and high-voltage, high-current pins, for direct VFD driving.

12.1.1 Features

The VFD controller/driver has the following features.

•

Maximum of 24 segment pins and 16 digit pins (20 segment pins, eight digit pins, and eight

switched segment/digit pins).

•

Brightness can be adjusted in eight steps (dimmer function).

•

Automatic shifting of displayed digit.

•

Digit pins and segment pins can be switched over to use as general-purpose high-voltage pins.

•

Optional key scan interval.

•

Interrupt generated when key scan interval starts.

12.1.2 Block Diagram

Figure 12-1 shows a block diagram of the VFD controller/driver.

Figure 12-1 Block Diagram of VFD Controller/Driver

Internal data bus

VFDR

DBR

VFSR

IRRKS

Display timing

generator circuit

VFD display RAM

Digit pins

Segment pins

Notation:

VFDR: VFD digit control register

DBR: Digit beginning register

VFSR: VFD segment control register

IRRKS: Key scan interrupt request flag (bit 6 of interrupt request register 3)

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HD6433713 Datasheet(PDF) 214 Page - Renesas Technology Corp