HSDP2110S, HSDP2111S, HSDP2112S, HSDP2113S, HSDP2114S, HSDP2115S

2006-01-23

9

Block Diagram

Functional Description

The display's user interface is organized into five memory

areas. They are accessed using the Flash Input, FL, and

address lines, A3 and A4. All the listed RAMs and Regis-

ters may be read or written through the data bus. See

Table „Memory Selection“. Each input pin is described in

Pin Definitions.

RST can be used to initialize display operation upon

power up or during normal operation. When activated,

RST will clear the Flash RAM and Control Word Register

(00H) and reset the internal counter. All eight display

memory locations will be set to 20H to show blanks in all

digits.

FL pin enables access to the Flash RAM. The Flash

RAM will set (D0=1) or reset (D0=0) flashing of the char-

acter addressed by A0–A2.

The 1 x 8 bit Control Word Register is loaded with

attribute data if A3=0.

The Control Word Logic decodes attribute data for

proper implementation.

Character ROM is designed for 128 ASCII characters.

The ROM is Mask Programmable for custom fonts.

The Clock Source could either be the internal oscillator

(CLKSEL=1) of the device or an external clock

(CLKSEL=0) could be an input from another HDSP211X

display for the synchronization of blinking for multiple dis-

plays.

The Display Multiplexer controls the Row Drivers so no

additional logic is required for a display system.

The Display has eight digits. Each digit has 35 LEDs

clustered into a 5 x 7 dot matrix.

IDBD5064

OSC

32

Counter

Counter

7

8 Digit Display

Drivers

Counter

128

Counter

3

Decode

RAM

Character

Character

RAM

D Latch

Holding

Register

Decode

Word

ROM

for Display

Decode

Character

(Read/Write)

Character

Decode

Register

Address

UDC

Bus

Row

ROM

4

64

4

RAM

16

16

UDC

Column

Latch

5

25

5

and

Controls

Cursor

Display

MUX

25

Word

Register

Control

Test

Self

Flash

RAM

Drivers

Column

Data

Five Basic Memory Areas

Character RAM

Stores either ASCII (Katakana)

character data or an UDC RAM

address

Flash RAM

1 x 8 RAM which stores Flash data

User-Defined

Character RAM

(UDC RAM)

Stores dot pattern for custom

characters

User-Defined Address

Register (UDC Address

Register)

Provides address to UDC RAM

when user is writing or reading

custom character

Control Word

Register

Enables adjustment of display

brightness, flash individual

characters, blink, self test or clearing

the display