MC141541

1

MOTOROLA

Enhanced Monitor On-Screen

Display

CMOS

The MC141541 is a high performance HCMOS device designed to interface

with a microcontroller unit to allow colored symbols or characters to be

displayed on a color monitor. The on–chip PLL allows both multi–system

operation and self–generation of system timing. It also minimizes the MCU’s

burden through its built–in 273 bytes display/control RAM. By storing a full

screen of data and control information, this device has the capability to carry out

‘screen–refresh’ without MCU supervision.

Since there is no spacing between characters, special graphics–oriented

characters can be generated by combining two or more character blocks. There

are two different resolutions that users can choose. By changing the number of

dots per horizontal line to 320 (CGA) or 480 (EGA), smaller characters with

higher resolution can be easily achieved.

Special functions such as character bordering or shadowing, multi–level

windows, double height and double width, and programmable vertical length of

character can also be incorporated. Furthermore, neither massive information

update nor extremely high data transmission rate are expected for normal on–

screen display operation, and serial protocols are implemented in lieu of any

parallel formats to achieve minimum pin count.

A special feature, character RAM fonts, is implemented in this MOSD

enhanced version (EMOSD). Users can download their own fonts and display

them at any time once the chip is powered on. There are two ways for users to

build and store fonts. One is a conventional approach to have masked ROM

fonts. A newer approach is to store the fonts in the EPROM accessed by the

MCU and then download them into the EMOSD character RAM. With this new

technique, users have more flexibility in preparing their fonts and the effective

number of fonts is greatly increased.

• Two Selectable Resolutions: 320 (CGA) and 480 (EGA) Dots per Line

• Fully Programmable Character Array of 10 Rows by 24 Columns

• 273 Bytes Direct Mapping Display RAM Architecture

• Internal PLL Generates a Wide–Ranged System Clock

• For High–End Monitor Application, Maximum Horizontal Frequency is

110 kHz (52.8 MHz Dot Clock at 480 Mode)

• Programmable Vertical Height of Character to Meet Multi–Sync

Requirement

• Programmable Vertical and Horizontal Positioning for Display Center

• 120 Characters and Graphic Symbols ROM and Eight Programmable

Character RAM

• 10 x 16 Dot Matrix Character

• Character–by–Character Color Selection

• A Maximum of Four Selectable Colors per Row

• Double Character Height and Double Character Width

• Character Bordering or Shadowing

• Three Fully Programmable Background Windows with Overlapping

Capability

• Provides a Clock Output Synchronous to the Incoming H Sync for External

PWM

• M_BUS (IIC) Interface with Address $7A

• Single Positive 5 V Supply

Order this document

by MC141541/D

MOTOROLA

SEMICONDUCTOR TECHNICAL DATA

PIN ASSIGNMENT

MC141541

P SUFFIX

PLASTIC DIP

CASE 648

ORDERING INFORMATION

MC141541P

Plastic DIP

13

14

15

16

9

10

11

12

5

4

3

2

1

8

7

6

FBKG

B

G

R

VSS

VDD

VFLB

HTONE/

VDD(A)

RP

VCO

SCL(SCK)

SDA(MOSI)

SS

HFLB

VSS(A)

PWMCK

REV 1

2/97

TN97031200