LPC1788 8bpp LCD Interfacing

[jtronix]

i want to interface LCD in 8bpp 332 mode.

anybody know connection diagram of LCD with uC?
which port no. are use for same.

also share 323 mode connection diagram

[ale500]

I'm also interested in this uC, so I have the User manual handy... let's see what I find:

From page 285/286:
It doesn't really seem to support 3:3:2 per-se, but you could use a palletized 5:6:5 scheme, that will give you 256 colors. But If you want to only use 8 color lines, maybe you will have to use palletized mode and just not bind the low bits of R, G and B.

The Table in page 288 describe which pins are needed for sync, clock, colors and so on.
The table in page 89 shows the mapping from Ports to LCD_xx.

In page 296 the table describes how the palette works and how it is stored, in page 306 the registers are described.

What do you think ?

[jtronix]

i'm using segger graphic library and if i configured segger for 16bit 565 color conversion mode then it takes more time to update LCD then 8 bit LCD driver.

Segger configuration:
16 bit configuration:
#define COLOR_CONVERSION   GUICC_565
#define DISPLAY_DRIVER     GUIDRV_LIN_16

8 bit configuration:
#define COLOR_CONVERSION   GUICC_332
#define DISPLAY_DRIVER     GUIDRV_LIN_8

update time of 8bit is 80% faster than 16bit so i want to interface LCD in 8 mode only in 332.

Result:
Sr No | Segger config | LCD Config | Conclusion
1        | 16bpp            |  16 bpp       | display properly but update time is too slow
2        | 8bpp              |  16 bpp       | not display proper shown in attach image (image.jpg) but update time is better
3        | 8bpp              |  8 bpp         | display blank only backlight turns ON

attach image :
A,b -> display two times
c --> display junk data

in 2nd case image is drawn twice and scale by 4 but it should display as shown in attach image(expected.jpg).

[ale500]

I would assume that you are setting the LCD controller yourself, aren't you ?
With such a config for 8 bit (GUIDRV_LIN_8) you get everything written to memory for 8 bpp. Nothing else happens. What you have to do is to configure LPC1788's LCD controller for palletized 8bpp using 565 bit per color. You also (may) have to upload the palette yourself, if you assume that those 3:3:2 mean Red:Green:Blue than for every 3:3:2 write a corresponding 5:6:5 to the palette entry:

0:0:0 -> 0:0:0
0:0:1 -> 0:0:3 (say you use bits 0, 1 together)
0:0:2 -> 0:0:28 (bits 4, 3 and 2 together)
0:0:3 -> 0:0:31 (blue, all bits set)

and so on