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)
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.

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Wed Oct 26 2016, 08:23 AM
is it possible to completly get the robot running from java code
Sun Oct 23 2016, 05:50 PM
mamata thakur
plz send full mini project report for ic 741&ic 555 tester
Wed Oct 19 2016, 03:30 PM
can you provide an explanation for the inverter 8051 code and how it works
Sat Oct 15 2016, 12:15 AM
@snaya. Create a thread in the 8051 forum for your questions
Fri Oct 14 2016, 10:00 AM
i m going to make a project with 8051and the name is scrolling led message display .now i wanna ask so many of questions.may be u can help me .so help me out
Fri Sep 30 2016, 10:40 AM
plz I want code for adc interfacing with8051
Sun Sep 25 2016, 04:41 AM
hi sir, could you help me regarding simple multiplication calculator?it should be include with buzzer. i use dragonplus. please
Sat Sep 24 2016, 05:49 PM
@Rus Ans .. what project ?
Sat Sep 24 2016, 05:48 PM
@engr1931 depends on type of scanner
Sat Sep 24 2016, 03:07 PM
Is it possible to send data from 2 barcode scanner to pc using serial port using 8051?



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Fri Oct 21 2016, 10:35 PM
Sat Oct 15 2016, 09:40 AM
Wed Oct 05 2016, 08:16 AM
Mon Oct 03 2016, 07:37 PM
Thu Sep 29 2016, 06:31 AM
Thu Sep 08 2016, 06:28 PM
Sat Aug 20 2016, 01:44 PM
Thu Aug 18 2016, 12:24 PM
Forum Activity
Pratik_Suthar Avatar
Posted By Pratik_Suthar
Thu Oct 13 2016, 12:39 PM
@martin the HEX file provided in the project is no...
ajay_bhargav Avatar
Posted By ajay_bhargav
Thu Oct 06 2016, 06:15 AM
Hi Phil, Do you want to add this to existing proje...
ajay_bhargav Avatar
Posted By ajay_bhargav
Thu Oct 06 2016, 06:13 AM
CE should be high when you go for reading mode/wai...
ajay_bhargav Avatar
Posted By ajay_bhargav
Thu Oct 06 2016, 06:03 AM
You can also use ESP8266 with its SDK to write app...
ExperimenterUK Avatar
Posted By ExperimenterUK
Mon Oct 03 2016, 11:15 PM
This is an old thread and the links no longer work...
martinsnc115877 Avatar
Posted By martinsnc115877
Wed Sep 14 2016, 12:51 PM
sir, i did your led scrolling mass display, and it...
ExperimenterUK Avatar
Posted By ExperimenterUK
Fri Sep 09 2016, 11:45 PM
The Hex file for this project is a bit too big for...
rajavarmanslr Avatar
Posted By rajavarmanslr
Thu Aug 18 2016, 01:40 PM
I have two 8051 that interfaces with nRF24l01. One...
rajavarmanslr Avatar
Posted By rajavarmanslr
Thu Aug 18 2016, 12:31 PM
I have two 8051 that interfaces with nRF24l01. One...