We have 18 bit TFT LCD want to interface to AM335x SOM

Santosh Bongane1

Other Parts Discussed in Thread: SN74AVC32T245

	LCD Connector Pin-out(Resistive) to SoM interface connector Pins
Pin #	Carrier Board connector ( JXX)	Type	LCD Pin details
1	VCC_5V	Power	VLED, 5V
2	VCC_5V	Power	VLED, 5V
3	BL_CTRL	O	Backlight brightness control
4	DGND	Power
5	DGND	Power
6	BASE_PER_3V3	Power	Carrier Board peripherals VCC
7	BASE_PER_3V3	Power	Carrier Board peripherals VCC
8	MODE	O	MODE
9	LCD_AC_BIAS_EN	O	Data enable
10	VSYNC	O	Vertical sync
11	HSYNC	O	Horizontal sync
12	DGND	Power
13	LCD_DATA15	O	Blue bit 5
14	LCD_DATA14	O	Blue bit 4
15	LCD_DATA13	O	Blue bit 3
16	DGND	Power
17	LCD_DATA12	O	Blue bit 2
18	LCD_DATA11	O	Blue bit 1
19	DGND	Power
20	DGND	Power
21	LCD_DATA10	O	Green bit 5
22	LCD_DATA9	O	Green bit 4
23	LCD_DATA8	O	Green bit 3
24	DGND	Power
25	LCD_DATA7	O	Green bit 2
26	LCD_DATA6	O	Green bit 1
27	LCD_DATA5	O	Green bit 0
28	DGND	Power
29	LCD_DATA4	O	Red bit 5
30	LCD_DATA3	O	Red bit 4
31	LCD_DATA2/SYSBOOT	Power	Red bit 3 / Boot source select control
32	DGND	Power
33	LCD_DATA1	O	Red Bit 2
34	LCD_DATA0	O	Red Bit 1
35	DGND	O	Red Bit 0
36	DGND	Power
37	LCD_PCLK	O	Clock
38	DGND	Power
39	LR	O	left / Right select
40	UD	O	Up/ Down select

AT070TN83 V.1( 最新).pdf

over 11 years ago

0 Biser Gatchev-XID over 11 years ago

TI__Guru**** 393215 points

What is your question? There is only a table in your post.

0 Santosh Bongane1 over 11 years ago in reply to Biser Gatchev-XID

Intellectual 375 points

My question is how to connect 18 bit RGB parallel LCD to AM335X sitara in 24 bit and 18 bit mode.. how to assign the LCD data line to LCD panel connector ( Pls see datasheet AT070TN83V.1 form Innolux).

if suppose i want to connect LVDS and Parallel RGB TFT LCD what is the right way to connect it to LCDC.

Can LCDC drive both Display buffer and LVDS transmiiter in parallel connection , but we can use only one LCD at a time,

pls. guide us to how to connect 24 bit mode AM335X connection to 18bit LCD panel.

AT070TN83 V.1( 最新).pdf

0 Biser Gatchev-XID over 11 years ago in reply to Santosh Bongane1

TI__Guru**** 393215 points

For an 18-bit LCD panel you must use the AM335X LCD controller in 24-bit mode (RGB888) and connect only bits 2-7 of each color to the LCD. The correct color assignments can be seen in the AM335X Errata, Rev. F, Figure 2.

You can connect a 24-bit LVDS transmitter in parallel to an 18-bit LCD panel (one at a time), but you cannot connect an 18-bit LVDS transmitter in parallel to a 24-bit LCD panel, as data on the LVDS will not be correct.

0 Santosh Bongane1 over 11 years ago in reply to Biser Gatchev-XID

Intellectual 375 points

I have posted pin assignment table on the last to tlast post , whether that pin configuration is correct for Innolux LCD.

datasheet for Innolux LCD attached.

For capacitive touch panel , what will be the connection schemes, for I2C, SPI.

USB Signal lines and VBUS needs isolation.

0 Biser Gatchev-XID over 11 years ago in reply to Santosh Bongane1

TI__Guru**** 393215 points

AM335X signals LCD_DATA[10:5] are your display GREEN[5:0]

AM335X signals LCD_DATA[15:11] are your display BLUE[5:1], LCD_DATA17 is BLUE0

AM335X signals LCD_DATA[4:0] are your display RED[5:1], LCD_DATA16 is RED0

0 Santosh Bongane1 over 11 years ago in reply to Biser Gatchev-XID

Intellectual 375 points

Thank you Biser,

Above stated signals LCD DATA to RGB connection is for 18 bit LCD when AM335X LCD controller is in 24 bit mode?

if Yes, then what is the connection sheme for 16 bit LCD display to 24 bit LCD conntroller?

pls reply urgently.

0 Santosh Bongane1 over 11 years ago in reply to Santosh Bongane1

Intellectual 375 points

Hi , Biser

We are having Innolux make 18 bit LCD panel ( datasheet attahced ) , and in datasheet it has 40 pin connector with connection scheme as per above posted table. RED0 and BLUE0 is connected to Ground.

Is it right way to connect RED0 abd Blue0 connect to Ground in 16 bit mode.

if not what is the correct connection scheme for 18 bit LCD display but 16 bit signal connection to 24 bit LCDC.

0 Biser Gatchev-XID over 11 years ago in reply to Santosh Bongane1

TI__Guru**** 393215 points

The LCD controller can support RGB565 (16-bit mode) natively, but the color assignment is different from 24-bit. Please see AM335X Errata Rev. F, Usage Note 3.1.1 for details.

0 Santosh Bongane1 over 11 years ago in reply to Biser Gatchev-XID

Intellectual 375 points

Above stated AM335X signals LCD DATA to RGB LCD display connection is for 18 bit LCD?.

i have asking the same question above at 11AM around

0 Biser Gatchev-XID over 11 years ago in reply to Santosh Bongane1

TI__Guru**** 393215 points

Please clarify is your LCD 18-bit or 16-bit? From all your posts this is the thing I cannot understand.

0 vinayak13 over 11 years ago in reply to Biser Gatchev-XID

Intellectual 625 points

I think Biser has replied to similar post http://e2e.ti.com/support/arm/sitara_arm/f/791/t/303632.aspx

0 Santosh Bongane1 over 11 years ago in reply to Biser Gatchev-XID

Intellectual 375 points

i have 18 bit LCD panel.

0 Biser Gatchev-XID over 11 years ago in reply to Santosh Bongane1

TI__Guru**** 393215 points

For 18-bit LCD panel the LCD controller has to be set in 24-bit (RGB888) mode and the color assignments are as follows:

AM335X signals LCD_DATA[10:5] are GREEN[5:0]

AM335X signals LCD_DATA[15:11] are BLUE[5:1], LCD_DATA17 is BLUE0

AM335X signals LCD_DATA[4:0] are RED[5:1], LCD_DATA16 is RED0

0 Santosh Bongane1 over 11 years ago in reply to Biser Gatchev-XID

Intellectual 375 points

Thanks Biser,

I got the answer . Just need one more clarifcation

We have two different types of TFT LCD Display , One is 24bit, 4.3 Inch and another one is 18bit , 7 Inch. As per need One LCD can be used at a time.(Two Different Connector on PCB)

Is it possible to connect 18 bit and 24 bit LCD to same display buffer(SN74AVC32T245)?.

RGB sequence remains same for both the LCD connection in hardware.

0 Biser Gatchev-XID over 11 years ago in reply to Santosh Bongane1

TI__Guru**** 393215 points

What is important here are the stub traces to the unused display connector. These may cause unwanted reflections on the LCD bus. You have to design the PCB in such a way, as to minimize stubs or eliminate them.

0 Santosh Bongane1 over 11 years ago in reply to Biser Gatchev-XID

Intellectual 375 points

???

Could You pls brief more, prefer some connections and drawing

0 Biser Gatchev-XID over 11 years ago in reply to Santosh Bongane1

TI__Guru**** 393215 points

I don't know what your idea is. If you have some schematic I can comment on it. For design ideas you can look at the AM335X reference designs: http://processors.wiki.ti.com/index.php/AM335xBoards

0 Santosh Bongane1 over 11 years ago in reply to Biser Gatchev-XID

Intellectual 375 points

My understanding is while connecting 18 bit LCD display LCDC should be in 24 bit mode and connecting LSB data signals.

And for 24 bit LCD Display , LCDC should be 24 bit mode but interchange the R and B signal Lines as per Errata rev F.

Pls confirm right or wrong

0 Biser Gatchev-XID over 11 years ago in reply to Santosh Bongane1

TI__Guru**** 393215 points

0 Santosh Bongane1 over 11 years ago in reply to Biser Gatchev-XID

Intellectual 375 points

1st pin mapping as per last post

AM335X signals LCD_DATA[10:5] are GREEN[5:0]

AM335X signals LCD_DATA[15:11] are BLUE[5:1], LCD_DATA17 is BLUE0

AM335X signals LCD_DATA[4:0] are RED[5:1], LCD_DATA16 is RED0

is it correct>?

2 second pin mapping

Or following Pin mapping is correct for any 18 bit LCD.

AM335X signals LCD_DATA[10:5] are GREEN[7:2]

AM335X signals LCD_DATA[15:11] are BLUE[7:3], LCD_DATA17 is BLUE0

AM335X signals LCD_DATA[4:0] are RED[7:3], LCD_DATA16 is RED0.

Manufacture datasheet shows pin mapping as per above 2 pin mapping assignement

0 Biser Gatchev-XID over 11 years ago in reply to Santosh Bongane1

TI__Guru**** 393215 points

Second one is correct.

0 Santosh Bongane1 over 11 years ago in reply to Biser Gatchev-XID

Intellectual 375 points

Hello extacly which one color assignment and LCD pin connection scheme i have to follow.

pls find two different schemes

AM335X	Signal Name	Connector Pins	LCD Panel Signal	SOM Pin
R1	LCD_DATA0	LCD_DATA0	Red Bit 1	15
R2	LCD_DATA1	LCD_DATA1	Red Bit 2	14
R3	LCD_DATA2	LCD_DATA2	Red Bit 3	17
R4	LCD_DATA3	LCD_DATA3	Red Bit 4	16
T1	LCD_DATA4	LCD_DATA4	Red Bit 5	19
T2	LCD_DATA5	LCD_DATA5	Green Bit 0	6
T3	LCD_DATA6	LCD_DATA6	Green Bit 1	9
T4	LCD_DATA7	LCD_DATA7	Green Bit 2	10
U1	LCD_DATA8	LCD_DATA8	Green Bit 3	11
U2	LCD_DATA9	LCD_DATA9	Green Bit 4	12
U3	LCD_DATA10	LCD_DATA10	Green Bit 5	13
U4	LCD_DATA11	LCD_DATA11	LCD Blue Bit 1	1
V2	LCD_DATA12	LCD_DATA12	LCD Blue Bit 2	2
V3	LCD_DATA13	LCD_DATA13	LCD Blue Bit 3	3
V4	LCD_DATA14	LCD_DATA14	LCD Blue Bit 4	4
T5	LCD_DATA15	LCD_DATA15	LCD Blue Bit 5	5
GND	LCD_DATA16	LCD_DATA16	Red Bit 0	GND
GND	LCD_DATA17	LCD_DATA17	LCD Blue Bit 0	GND
U5	LCD_VSYNC	LCD_VSYNC	LCD_VSYNC	24
R5	LCD_HSYNC	LCD_HSYNC	LCD_HSYNC	20
V5	LCD_PCLK	LCD_PCLK	LCD_PCLK	22
R6	LCD_AC_BIAS_EN	LCD_AC_BIAS_EN	LCD_AC_BIAS_EN	21

and other scheme

AM335X	Signal Name	Connector Pins	LCD Panel Signal	SOM Pin
R1	LCD_DATA0	LCD_DATA0	Red Bit 3	15
R2	LCD_DATA1	LCD_DATA1	Red Bit 4	14
R3	LCD_DATA2	LCD_DATA2	Red Bit 5	17
R4	LCD_DATA3	LCD_DATA3	Red Bit 6	16
T1	LCD_DATA4	LCD_DATA4	Red Bit 7	19
T2	LCD_DATA5	LCD_DATA5	Green Bit 2	6
T3	LCD_DATA6	LCD_DATA6	Green Bit 3	9
T4	LCD_DATA7	LCD_DATA7	Green Bit 4	10
U1	LCD_DATA8	LCD_DATA8	Green Bit 5	11
U2	LCD_DATA9	LCD_DATA9	Green Bit 6	12
U3	LCD_DATA10	LCD_DATA10	Green Bit 7	13
U4	LCD_DATA11	LCD_DATA11	LCD Blue Bit 3	1
V2	LCD_DATA12	LCD_DATA12	LCD Blue Bit 4	2
V3	LCD_DATA13	LCD_DATA13	LCD Blue Bit 5	3
V4	LCD_DATA14	LCD_DATA14	LCD Blue Bit 6	4
T5	LCD_DATA15	LCD_DATA15	LCD Blue Bit 7	5
	LCD_DATA16	LCD_DATA16	Red Bit 0	GND
	LCD_DATA17	LCD_DATA17	LCD Blue Bit 0	GND
U5	LCD_VSYNC	LCD_VSYNC	LCD_VSYNC	24
R5	LCD_HSYNC	LCD_HSYNC	LCD_HSYNC	20
V5	LCD_PCLK	LCD_PCLK	LCD_PCLK	22
R6	LCD_AC_BIAS_EN	LCD_AC_BIAS_EN	LCD_AC_BIAS_EN	21

0 Santosh Bongane1 over 11 years ago in reply to Biser Gatchev-XID

Intellectual 375 points

sir pls. help for the connection of 18 bit LCD as per follwoing scheme

AM335X	Signal Name	Connector Pins	LCD Panel Signal	SOM Pin
R1	LCD_DATA0	LCD_DATA0	Red Bit 3	15
R2	LCD_DATA1	LCD_DATA1	Red Bit 4	14
R3	LCD_DATA2	LCD_DATA2	Red Bit 5	17
R4	LCD_DATA3	LCD_DATA3	Red Bit 6	16
T1	LCD_DATA4	LCD_DATA4	Red Bit 7	19
T2	LCD_DATA5	LCD_DATA5	Green Bit 2	6
T3	LCD_DATA6	LCD_DATA6	Green Bit 3	9
T4	LCD_DATA7	LCD_DATA7	Green Bit 4	10
U1	LCD_DATA8	LCD_DATA8	Green Bit 5	11
U2	LCD_DATA9	LCD_DATA9	Green Bit 6	12
U3	LCD_DATA10	LCD_DATA10	Green Bit 7	13
U4	LCD_DATA11	LCD_DATA11	LCD Blue Bit 3	1
V2	LCD_DATA12	LCD_DATA12	LCD Blue Bit 4	2
V3	LCD_DATA13	LCD_DATA13	LCD Blue Bit 5	3
V4	LCD_DATA14	LCD_DATA14	LCD Blue Bit 6	4
T5	LCD_DATA15	LCD_DATA15	LCD Blue Bit 7	5
	LCD_DATA16	LCD_DATA16	Red Bit 0	GND
	LCD_DATA17	LCD_DATA17	LCD Blue Bit 0	GND
U5	LCD_VSYNC	LCD_VSYNC	LCD_VSYNC	24
R5	LCD_HSYNC	LCD_HSYNC	LCD_HSYNC	20
V5	LCD_PCLK	LCD_PCLK	LCD_PCLK	22
R6	LCD_AC_BIAS_EN	LCD_AC_BIAS_EN	LCD_AC_BIAS_EN	21

0 Santosh Bongane1 over 11 years ago in reply to Santosh Bongane1

Intellectual 375 points

As mentioned above connection between LCD controller and LCD panel .

is ti correct one ?

if the LCD controller is in 24 bit mode then LCD panel connection as per above table is correct?

0 Santosh Bongane1 over 10 years ago in reply to Biser Gatchev-XID

Intellectual 375 points

Hi Biesr,

For 16 bit TFT LCD whether we have to connect the LCDDATA pins to LCD panel signals as per below.

pls. confirm,

AM335X signals LCD_DATA[10:5] are your display GREEN[5:0]
AM335X signals LCD_DATA[15:11] are your display BLUE[5:1], LCD_DATA17 is BLUE0
AM335X signals LCD_DATA[4:0] are your display RED[5:1], LCD_DATA16 is RED0

0 Biser Gatchev-XID over 10 years ago in reply to Santosh Bongane1

TI__Guru**** 393215 points

You can find the correct color assignments in the document AM335X Errata Rev. F, section 3.1.

0 Santosh Bongane1 over 10 years ago in reply to Biser Gatchev-XID

Intellectual 375 points

Thanks,

That means MSB bits of Display should be connected to MSB bits of LCD DATA on Controller side.

0 Biser Gatchev-XID over 10 years ago in reply to Santosh Bongane1

TI__Guru**** 393215 points

Yes.

Processors

Processors forum

We have 18 bit TFT LCD want to interface to AM335x SOM