AM1808 24 bit RGB TFT LCD

Moha Deeb1

Other Parts Discussed in Thread: AM1808

Hi,

We are developing and industrial controller based on AM1808, we want to connect 24 Bit RGB TFT LCD to the 16 Bit LCDC port of the AM1808, should we use the LSB or the MSB data bits from the LCD, is the below configuration correct?

NC -> B0 NC -> G0 NC -> R0

NC -> B1 NC -> G1 NC -> R1

NC -> B2 LCD_D5 -> G2 NC -> R2

LCD_D0 -> B3 LCD_D6 -> G3 LCD_D11 -> R3

LCD_D1 -> B4 LCD_D7 -> G4 LCD_D12 -> R4

LCD_D2 -> B5 LCD_D8 -> G5 LCD_D13 -> R5

LCD_D3 -> B6 LCD_D9 -> G6 LCD_D14 -> R6

LCD_D4 -> B7 LCD_D10 -> G7 LCD_D15 -> R7

Thanks.

over 12 years ago

0 Pubesh over 12 years ago

TI__Mastermind 20790 points

Moha,

Refer the Figure 24-7. 16-BPP Data Memory Organization (TFT Mode Only)
http://www.ti.com/lit/spruh77
http://www.ti.com/lit/spruh82
Register: RASTER_CTRL
Field: TFT_ALT_MAP
Output pixel data for 1, 2, 4, and 8 BPP will be right aligned on LCD_D[11:0].
For example, R3 R2 R1 R0 G3 G2 G1 G0 B3 B2 B1 B0

Refer the below wiki page links for Raster Mode
http://processors.wiki.ti.com/index.php/StarterWare_LCDC
http://processors.wiki.ti.com/index.php/AM18XX_SitaraWare_Graphics#Raster_Programming
http://processors.wiki.ti.com/index.php/OMAP-L1x/C674x/AM1x_LCD_Controller_(LCDC)_Throughput_and_Optimization_Techniques

4532.evmomapl138_lcd_raster.c

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//-----------------------------------------------------------------------------
// \file    evmomapl138_raster.c
// \brief   implementation of the raster LCD driver for the OMAP-L138 EVM.
//
//-----------------------------------------------------------------------------
#include "stdio.h"
#include "types.h"
#include "evmomapl138.h"
#include "evmomapl138_timer.h"
#include "evmomapl138_gpio.h"
#include "evmomapl138_lcdc.h"
#include "evmomapl138_lcd_raster.h"
//-----------------------------------------------------------------------------
// Private Defines and Macros
//-----------------------------------------------------------------------------
#define PINMUX_LCD_D_BUS_0_REG      16
#define PINMUX_LCD_D_BUS_1_REG      17
#define PINMUX_LCD_D_BUS_2_REG      18
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//-----------------------------------------------------------------------------
// \file    evmomapl138_raster.c
// \brief   implementation of the raster LCD driver for the OMAP-L138 EVM.
//
//-----------------------------------------------------------------------------
#include "stdio.h"
#include "types.h"
#include "evmomapl138.h"
#include "evmomapl138_timer.h"
#include "evmomapl138_gpio.h"
#include "evmomapl138_lcdc.h"
#include "evmomapl138_lcd_raster.h"

//-----------------------------------------------------------------------------
// Private Defines and Macros
//-----------------------------------------------------------------------------
#define PINMUX_LCD_D_BUS_0_REG      16
#define PINMUX_LCD_D_BUS_1_REG      17
#define PINMUX_LCD_D_BUS_2_REG      18
#define PINMUX_LCD_CONTROL_0_REG    18
#define PINMUX_LCD_CONTROL_1_REG    19

#define PINMUX_LCD_D_BUS_0_MASK     (0xFFFFFF00)
#define PINMUX_LCD_D_BUS_1_MASK     (0xFFFFFFFF)
#define PINMUX_LCD_D_BUS_2_MASK     (0x000000FF)
#define PINMUX_LCD_CONTROL_0_MASK   (0xFF000000)
#define PINMUX_LCD_CONTROL_1_MASK   (0x000000FF)

#define PINMUX_LCD_D_BUS_0_VALUE    (0x22222200)
#define PINMUX_LCD_D_BUS_1_VALUE    (0x22222222)
#define PINMUX_LCD_D_BUS_2_VALUE    (0x00000022)
#define PINMUX_LCD_CONTROL_0_VALUE  (0x22000000)
#define PINMUX_LCD_CONTROL_1_VALUE  (0x02000022)

#define PINMUX_LCD_PWR_REG          (5)
#define PINMUX_LCD_PWR_MASK         (0xF0000000)
#define PINMUX_LCD_PWR_VALUE        (0x80000000)
#define PINMUX_BACKLIGHT_PWR_REG    (5)
#define PINMUX_BACKLIGHT_PWR_MASK   (0x0000000F)
#define PINMUX_BACKLIGHT_PWR_VALUE  (0x00000008)
#define PINMUX_BACKLIGHT_PWM_REG    (1)
#define PINMUX_BACKLIGHT_PWM_MASK   (0x0000000F)
#define PINMUX_BACKLIGHT_PWM_VALUE  (0x00000008)

#define LCD_PWR_GPIO_BANK           (2)
#define LCD_PWR_GPIO_PIN            (8)
#define BACKLIGHT_PWR_GPIO_BANK     (2)
#define BACKLIGHT_PWR_GPIO_PIN      (15)
#define BACKLIGHT_PWM_GPIO_BANK     (0)
#define BACKLIGHT_PWM_GPIO_PIN      (7)

//-----------------------------------------------------------------------------
// Private Function Prototypes
//-----------------------------------------------------------------------------
static uint32_t raster_config(void);
static uint32_t enable_lcdc(void);
static uint32_t disable_lcdc(void);
static uint32_t disable_lcd_power(void);
static uint32_t disable_lcd_backlight(void);
static uint32_t enable_lcd_power(void);
static uint32_t enable_lcd_backlight(void);

//-----------------------------------------------------------------------------
// Public Function Definitions
//-----------------------------------------------------------------------------

//-----------------------------------------------------------------------------
// \brief   initialize the lcd controller for raster use.
//
// \param   none.
//
// \return  uint32_t
//    ERR_NO_ERROR - everything is ok...lcdc ready to use.
//    ERR_INIT_FAIL - something happened during initialization.
//-----------------------------------------------------------------------------
uint32_t RASTER_init(void)
{
   uint32_t rtn = ERR_NO_ERROR;

   /* Set MUX_MODE on UI GPIO expander to LCD */
   EVMOMAPL138_pinmuxConfig(PINMUX_LCD_D_BUS_0_REG, PINMUX_LCD_D_BUS_0_MASK, PINMUX_LCD_D_BUS_0_VALUE);
   EVMOMAPL138_pinmuxConfig(PINMUX_LCD_D_BUS_1_REG, PINMUX_LCD_D_BUS_1_MASK, PINMUX_LCD_D_BUS_1_VALUE);
   EVMOMAPL138_pinmuxConfig(PINMUX_LCD_D_BUS_2_REG, PINMUX_LCD_D_BUS_2_MASK, PINMUX_LCD_D_BUS_2_VALUE);
   EVMOMAPL138_pinmuxConfig(PINMUX_LCD_CONTROL_0_REG, PINMUX_LCD_CONTROL_0_MASK, PINMUX_LCD_CONTROL_0_VALUE);
   EVMOMAPL138_pinmuxConfig(PINMUX_LCD_CONTROL_1_REG, PINMUX_LCD_CONTROL_1_MASK, PINMUX_LCD_CONTROL_1_VALUE);

   // configure the gpio pins used for lcd power, backlight power and pwm.
   EVMOMAPL138_pinmuxConfig(PINMUX_LCD_PWR_REG, PINMUX_LCD_PWR_MASK, PINMUX_LCD_PWR_VALUE);
   EVMOMAPL138_pinmuxConfig(PINMUX_BACKLIGHT_PWR_REG, PINMUX_BACKLIGHT_PWR_MASK, PINMUX_BACKLIGHT_PWR_VALUE);
   EVMOMAPL138_pinmuxConfig(PINMUX_BACKLIGHT_PWM_REG, PINMUX_BACKLIGHT_PWM_MASK, PINMUX_BACKLIGHT_PWM_VALUE);
   GPIO_setDir(LCD_PWR_GPIO_BANK, LCD_PWR_GPIO_PIN, GPIO_OUTPUT);
   GPIO_setDir(BACKLIGHT_PWR_GPIO_BANK, BACKLIGHT_PWR_GPIO_PIN, GPIO_OUTPUT);
   GPIO_setDir(BACKLIGHT_PWM_GPIO_BANK, BACKLIGHT_PWM_GPIO_PIN, GPIO_OUTPUT);
   
   // initially set the backlight pwm high.
   GPIO_setOutput(BACKLIGHT_PWM_GPIO_BANK, BACKLIGHT_PWM_GPIO_PIN, OUTPUT_HIGH);

   // enable power and setup lcdc.
   disable_lcdc();
   enable_lcdc();
   raster_config();

   // power down the display kit.
   disable_lcd_backlight();
   disable_lcd_power();
   USTIMER_delay(300000);

   // power-up the display kit following the correct sequence.
   enable_lcd_power();
   USTIMER_delay(300000);
   enable_lcd_backlight();

   return (rtn);
}

//-----------------------------------------------------------------------------
// \brief   plot an x, y pixel on the graphics LCD.
//
// \param   uint16_t x - .
//
// \param   uint16_t y - .
//
// \param   uint16_t pixel_data - .
//
// \return  none.
//-----------------------------------------------------------------------------
void RASTER_plot(uint16_t x, uint16_t y, uint16_t pixel_data)
{
   *((uint16_t *)(FRAMEBUF_PIXEL_BASE + y * (LCD_WIDTH * 2) + (x << 1))) = pixel_data;
}

//-----------------------------------------------------------------------------
// \brief   clear the graphics LCD to the input color.
//
// \param   uint16_t color - .
//
// \return  none.
//-----------------------------------------------------------------------------
void RASTER_clear(uint16_t color)
{
   uint32_t x, y;

   // Paint the background
   for (x = 0; x < LCD_WIDTH; x++)
      for (y = 0; y < LCD_HEIGHT; y++)
         RASTER_plot(x, y, color);
}

//-----------------------------------------------------------------------------
// Private Function Definitions
//-----------------------------------------------------------------------------

//-----------------------------------------------------------------------------
//
//-----------------------------------------------------------------------------
uint32_t raster_config( void )
{
   uint32_t x;
   uint16_t *pdata;

   /*
   *  LCD Panel
   */
   LCDC->RASTER_CTRL       &= 0xfffffffe;         // Turn raster controller off

   LCDC->LCD_STAT           = 0x000003ff;         // Clear status bits

#ifdef DISPLAY_3_6
    // 18.75 MHz, raster mode pixel clock, 320 x 240 viewable frame
   LCDC->LCD_CTRL           = 0x00001101;    // PCLK = 150MHz / 8 = 8.824 MHz, raster mode
   LCDC->RASTER_TIMING_0    = (0x14 << 24)
                           | (0x14 << 16)
                           | (0x14 << 10)
                           | (0x13 << 4);    // HBP = 0x14; HFP = 0x14; HSW = 0x14; PPL = 0x13
   LCDC->RASTER_TIMING_1    = (0x03 << 24)
                           | (0x03 << 16)
                           | (0x02 << 10)
                           | (0xEF);         // VBP = 0x3; VFP = 0x3; VSW = 0x2: LPP = 0xEF;
   LCDC->RASTER_TIMING_2    = 0x02700000;
#endif



#ifdef DISPLAY_4_3
   // 8.824 MHz, raster mode pixel clock, 480 x 272 viewable frame
   LCDC->LCD_CTRL           = 0x00001101;    // PCLK = 150MHz / 17 = 8.824 MHz, raster mode
   LCDC->RASTER_TIMING_0    = (0x01 << 24)
                           | (0x02 <<16)
                           | (0x29 << 10)
                           | (0x1D << 4);    // HBP = 0x01; HFP = 0x02; HSW = 0x29; PPL = 0x1D
   LCDC->RASTER_TIMING_1    = (0x03 << 24)
                           | (0x02 << 16)
                           | (0x0A << 10)
                           | (0x10F);        // VBP = 0x3; VFP = 0x2; VSW = 0xA: LPP = 0x10F;
   LCDC->RASTER_TIMING_2    = 0x02700000;
#endif

#ifdef DISPLAY_6_4
   // 18.75 MHz, raster mode pixel clock, 640 x 480 viewable frame
   LCDC->LCD_CTRL           = 0x00000801;    // PCLK = 150MHz / 8 = 18.75 MHz, raster mode
   LCDC->RASTER_TIMING_0    = (0x19 << 24)
                           | (0x89 << 16)
                           | (0x31 << 10)
                           | (0x27 << 4);    // HBP = 0x19; HFP = 0x89; HSW = 0x31; PPL = 0x27
   LCDC->RASTER_TIMING_1    = (0x1F << 24)
                           | (0x20 <<16)
                           | (0x02 <<10)
                           | (0x1DF);        // VBP = 0x1F; VFP = 0x20; VSW = 0x2: LPP = 0x1DF;
   LCDC->RASTER_TIMING_2    = 0x02700000;
#endif

   LCDC->LCDDMA_CTRL        = 0x00000020;
   LCDC->LCDDMA_FB0_BASE    = FRAMEBUF_BASE;     // Frame buffer start
   LCDC->LCDDMA_FB0_CEILING = FRAMEBUF_PIXEL_BASE + (LCD_WIDTH * LCD_HEIGHT * 2) - 4; // Frame buffer end
   LCDC->RASTER_CTRL        = 0x01000080;         // 6-5-6 mode,
   LCDC->RASTER_CTRL       |= 0x00000001;         // Enable controller

   /* Palette */
   pdata = (uint16_t *)FRAMEBUF_PALETTE_BASE;
   *pdata++ = 0x4000;
   for (x = 0; x < 15; x++)
   {
      *pdata++ = 0x0000;
   }

   return (ERR_NO_ERROR);
}

//-----------------------------------------------------------------------------
// Enable the LCD Hardware.
//-----------------------------------------------------------------------------
uint32_t enable_lcdc( void )
{
   EVMOMAPL138_lpscTransition(PSC1, DOMAIN0, LPSC_LCDC, PSC_ENABLE);

   return (ERR_NO_ERROR);
}

//-----------------------------------------------------------------------------
// Disable the LCD Hardware.
//-----------------------------------------------------------------------------
uint32_t disable_lcdc( void )
{
   EVMOMAPL138_lpscTransition(PSC1, DOMAIN0, LPSC_LCDC, PSC_DISABLE);

   return (ERR_NO_ERROR);
}

//-----------------------------------------------------------------------------
// clear the gpio pin that controls the lcd power.
//-----------------------------------------------------------------------------
uint32_t disable_lcd_power( void )
{
   return (GPIO_setOutput(LCD_PWR_GPIO_BANK, LCD_PWR_GPIO_PIN, OUTPUT_LOW));
}

//-----------------------------------------------------------------------------
// clear the gpio pin that controls the backlight power.
//-----------------------------------------------------------------------------
uint32_t disable_lcd_backlight( void )
{
   return (GPIO_setOutput(BACKLIGHT_PWR_GPIO_BANK, BACKLIGHT_PWR_GPIO_PIN, OUTPUT_LOW));
}

//-----------------------------------------------------------------------------
// set the gpio pin that controls the lcd power.
//-----------------------------------------------------------------------------
uint32_t enable_lcd_power( void )
{
   uint32_t i;

   GPIO_setOutput(LCD_PWR_GPIO_BANK, LCD_PWR_GPIO_PIN, OUTPUT_HIGH);

   /* For 4.3" display, we need a few ms before we turn on backlight, or */
   /* the display panel logic goes out to lunch.                         */
   for (i = 0; i < 300; i++)
   {
      USTIMER_delay(1000);
   }

   return(ERR_NO_ERROR);
}

//-----------------------------------------------------------------------------
// set the gpio pin that controls the backlight power.
//-----------------------------------------------------------------------------
uint32_t enable_lcd_backlight( void )
{
   return (GPIO_setOutput(BACKLIGHT_PWR_GPIO_BANK, BACKLIGHT_PWR_GPIO_PIN, OUTPUT_HIGH));
}

0 Antony Samsunil over 12 years ago in reply to Pubesh

TI__Expert 4760 points

Hi Moha,

You need to use LSB and the below configuration is correct for 16-Bit RGB565 Interface to 24-Bit RGB 888 TFT LCD usually the unused LCD pins are grounded.

One thing you will see on an LCD with only 16 bits or source color (5 red, 6 green and 5 blue) is severe banding artifacts when displaying smooth shaded regions or color gradients. This is not an issue for things like menu displays but looks terrible for video applications.

Regards

Antony

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0 Moha Deeb1 over 12 years ago in reply to Antony Samsunil

Intellectual 270 points

got it.

Thanks Pubesh and Antony.

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AM1808 24 bit RGB TFT LCD