TOPWAY

LCD Module User Manual

LM3121

www.topwaysz.com

Document Name: LM3121-Manual-Rev0.2

Page: 4 of 9

1.4

Terminal Functions

Pin

No.

Pin

Name

I/O

Descriptions

1

VSS

Power

Negative Power Supply, Ground (0V)

2

VDD

Power

Positive Power Supply

3

V0

Input

LCD Contrast Reference

4

VOUT Power

LCD Booster Output for V0

5

/RES

Input

Reset signal (*2)

Resetting: rising edge and falling edge of RES

Normal Running: /RES=High

6

DB7

:

:

13

DB0

I/O

Bi-directional Data Bus for display data or instruction data

14

R/W

Input

Read /Write Control Signal

15

A0

Input

A0 = H; DB0 – DB7 = Display Data

A0 = L; DB0 – DB7 = Instruction Data

16

E1

Input

Enable Signal for left section of the LCD module

17

E2

Input

Enable Signal for middle section of the LCD module

18

E3

Input

Enable Signal for right section of the LCD module

19

BLA

Power

Positive Power for LED backlight

20

BLK

Power

Negative Power for LED backlight

Note:

*1.

Display or instruction data could write into the LCD module’s driver/controllers individually or at the same time.

*2.

Never keep RES signal at Low level for more than 1ms, otherwise unexpected high current drawn will occur due

to the internal data collision. It may permanently damage the LCD module.