Commands and Instruction set

Only the instruction register (IR) and the data register (DR) of the LCD can be controlled by the MCU. Before starting the internal operation of the LCD, control information is temporarily stored into these registers to allow interfacing with various MCUs, which operate at different speeds, or various peripheral control devices. The internal operation of the LCD is determined by signals sent from the MCU. These signals, which include register selection signal (RS), read/write signal (R/W), and the data bus (DB0 to DB7), make up the LCD instructions (Table 3). There are four categories of instructions that:


  • Designate LCD functions, such as display format, data length, etc.
  • Set internal RAM addresses
  • Perform data transfer with internal RAM
  • Perform miscellaneous functions



Table 3: Command and Instruction set for LCD type HD44780


Although looking at the table you can make your own commands and test them. Below is a breif list of useful commands which are used frequently while working on the LCD.


No. Instruction Hex Decimal
1Function Set: 8-bit, 1 Line, 5x7 Dots0x3048
2Function Set: 8-bit, 2 Line, 5x7 Dots0x3856
3Function Set: 4-bit, 1 Line, 5x7 Dots0x2032
4Function Set: 4-bit, 2 Line, 5x7 Dots0x2840
5Entry Mode0x066
6Display off Cursor off
(clearing display without clearing DDRAM content)
0x088
7Display on Cursor on0x0E14
8Display on Cursor off0x0C12
9Display on Cursor blinking0x0F15
10Shift entire display left0x1824
11Shift entire display right0x1C30
12Move cursor left by one character0x1016
13Move cursor right by one character0x1420
14Clear Display (also clear DDRAM content)0x011
15Set DDRAM address or coursor position on display0x80 + address*128 + address*
16Set CGRAM address or set pointer to CGRAM location0x40 + address**64 + address**
Table 4: Frequently used commands and instructions for LCD
* DDRAM address given in LCD basics section see Figure 2,3,4
** CGRAM address from 0x00 to 0x3F, 0x00 to 0x07 for char1 and so on..

The table above will help you while writing programs for LCD. But after you are done testing with the table 4, i recommend you to use table 3 to get more grip on working with LCD and trying your own commands. In the next section of the tutorial we will see the initialization with some of the coding examples in C as well as assembly.

Share it! Like it!

Conversation

Fri Apr 26 2019, 03:51 AM
charmdatetqt
cooking
Tue Apr 23 2019, 09:30 PM
Kenneth Evans
Kind Regards,
ExperimenterUK
Sun Apr 14 2019, 07:52 PM
@hassan malik post your problem in the "General help Guidance and Discussion" forum
Sun Apr 14 2019, 02:06 PM
RAJESH MAPARi
please send me code to interface atmega32 with 24c1024 serial eeprom
Sun Apr 14 2019, 10:33 AM
hassan malik
hello sir i installed proteus 7.8 professional on window 7 ultimate and window 10 but there would be same errors onn both windows. the error is bad license key.please any one help me
Sun Apr 14 2019, 10:32 AM
hassan malik
hello sir i installed proteus 7.8 professional on window 7 ultimate and window 10 but there would be same errors onn both windows. the error is bad license key.
ExperimenterUK
Sat Apr 06 2019, 02:59 PM
@deshrar. Please post your question in 8051 forum
Sat Apr 06 2019, 04:43 AM
deshraj
hallo mam.. i have downloded gsm notice board code its running fine on lcd but how so send msg to the module . i mean format of password and msg.. thank you
kevinharsha
Wed Apr 03 2019, 01:38 PM
Can i see the circuit diagram for the music tone library 8051 project?
ExperimenterUK
Tue Apr 02 2019, 11:45 PM
@Prudhvi. Please post your request in 8051 forum

Downloads

Comments

obibikwe
Fri Apr 19 2019, 05:55 PM
gigyani
Thu Apr 18 2019, 01:43 AM
Deekshaaan
Wed Apr 17 2019, 03:02 PM
popli
Mon Apr 08 2019, 02:31 AM
kevinharsha
Wed Apr 03 2019, 04:33 PM
WWSIERT
Wed Apr 03 2019, 01:02 PM
Ausonagara
Mon Apr 01 2019, 10:42 AM
tutu10
Tue Mar 12 2019, 07:11 AM

Online

Guests: 27, Members: 0 ...

most ever online: 182184
(Members: , Guests: 182184) on 06 Aug 2010: 05:37 AM

Members: 38059
Newest member: obibikwe
Forum Activity
ExperimenterUK Avatar
Posted By ExperimenterUK
Thu Apr 25 2019, 08:20 PM
I made a minor change, it works in Proteus.Try the...
gigyani Avatar
Posted By gigyani
Thu Apr 25 2019, 01:17 AM
when i add cufirst.hex its not working.after 2-3 s...
ExperimenterUK Avatar
Posted By ExperimenterUK
Wed Apr 24 2019, 12:29 AM
http://www.8051projects.net/download-d205-electron...
gigyani Avatar
Posted By gigyani
Tue Apr 23 2019, 09:22 PM
How to enter the electronic voting machine into vo...
Ansh12 Avatar
Posted By Ansh12
Mon Apr 22 2019, 09:12 AM
Then flash the led when you get any input on B0.Le...
ExperimenterUK Avatar
Posted By ExperimenterUK
Fri Apr 19 2019, 05:35 PM
The full error is control_unit.asm(1294): error A4...
gigyani Avatar
Posted By gigyani
Thu Apr 18 2019, 10:09 PM
I'm using keil uvision5. attached is the rar file ...
ExperimenterUK Avatar
Posted By ExperimenterUK
Thu Apr 18 2019, 04:58 PM
Please zip your full code and post it.Which assemb...
gigyani Avatar
Posted By gigyani
Thu Apr 18 2019, 02:01 AM
STATREAD:MOV A, #WTCMD ;LOAD WRITE CO...
Deekshaaan Avatar
Posted By Deekshaaan
Wed Apr 17 2019, 04:26 PM
hello i downloaded the frequency counter project f...