Overview

The MCUXpresso SDK provides a peripheral driver for the Enhanced LCD Interface(eLCDIF)

The Enhanced LCD Interface supports MPU mode, VSYNC mode, RGB mode (or DOTCLK mode), and DVI mode. The current eLCDIF driver only supports RGB mode.

Typical use case

Frame buffer update

The function ELCDIF_SetNextBufferAddr sets the next frame to show to eLCDIF, the eLCDIF loads the new frame and sets the interrupt kELCDIF_CurFrameDone. If no new frame is set, the old one is displayed.

Refer to the driver examples codes located at <SDK_ROOT>/boards/<BOARD>/driver_examples/elcdif

Alpha surface

The alpha surface can be enabled to add an extra overlay on the normal display buffer. In this example, the alpha surface is enabled, and the alpha value is updated after every frame loaded to eLCDIF.

Refer to the driver examples codes located at <SDK_ROOT>/boards/<BOARD>/driver_examples/elcdif

Data Structures
struct	elcdif_pixel_format_reg_t
	The register value when using different pixel format. More...

struct	elcdif_rgb_mode_config_t
	eLCDIF configure structure for RGB mode (DOTCLK mode). More...

struct	elcdif_as_buffer_config_t
	eLCDIF alpha surface buffer configuration. More...

struct	elcdif_as_blend_config_t
	eLCDIF alpha surface blending configuration. More...

Enumerations
enum	_elcdif_polarity_flags { kELCDIF_VsyncActiveLow = 0U, kELCDIF_VsyncActiveHigh = LCDIF_VDCTRL0_VSYNC_POL_MASK, kELCDIF_HsyncActiveLow = 0U, kELCDIF_HsyncActiveHigh = LCDIF_VDCTRL0_HSYNC_POL_MASK, kELCDIF_DataEnableActiveLow = 0U, kELCDIF_DataEnableActiveHigh = LCDIF_VDCTRL0_ENABLE_POL_MASK, kELCDIF_DriveDataOnFallingClkEdge = 0U, kELCDIF_DriveDataOnRisingClkEdge = LCDIF_VDCTRL0_DOTCLK_POL_MASK }
	eLCDIF signal polarity flags More...

enum	_elcdif_interrupt_enable { kELCDIF_BusMasterErrorInterruptEnable = LCDIF_CTRL1_BM_ERROR_IRQ_EN_MASK, kELCDIF_TxFifoOverflowInterruptEnable = LCDIF_CTRL1_OVERFLOW_IRQ_EN_MASK, kELCDIF_TxFifoUnderflowInterruptEnable = LCDIF_CTRL1_UNDERFLOW_IRQ_EN_MASK, kELCDIF_CurFrameDoneInterruptEnable, kELCDIF_VsyncEdgeInterruptEnable }
	The eLCDIF interrupts to enable. More...

enum	_elcdif_interrupt_flags { kELCDIF_BusMasterError = LCDIF_CTRL1_BM_ERROR_IRQ_MASK, kELCDIF_TxFifoOverflow = LCDIF_CTRL1_OVERFLOW_IRQ_MASK, kELCDIF_TxFifoUnderflow = LCDIF_CTRL1_UNDERFLOW_IRQ_MASK, kELCDIF_CurFrameDone, kELCDIF_VsyncEdge = LCDIF_CTRL1_VSYNC_EDGE_IRQ_MASK }
	The eLCDIF interrupt status flags. More...

enum	_elcdif_status_flags { kELCDIF_LFifoFull = LCDIF_STAT_LFIFO_FULL_MASK, kELCDIF_LFifoEmpty = LCDIF_STAT_LFIFO_EMPTY_MASK, kELCDIF_TxFifoFull = LCDIF_STAT_TXFIFO_FULL_MASK, kELCDIF_TxFifoEmpty = LCDIF_STAT_TXFIFO_EMPTY_MASK }
	eLCDIF status flags More...

enum	elcdif_pixel_format_t { kELCDIF_PixelFormatRAW8 = 0, kELCDIF_PixelFormatRGB565 = 1, kELCDIF_PixelFormatRGB666 = 2, kELCDIF_PixelFormatXRGB8888 = 3, kELCDIF_PixelFormatRGB888 = 4 }
	The pixel format. More...

enum	elcdif_lcd_data_bus_t { kELCDIF_DataBus8Bit = LCDIF_CTRL_LCD_DATABUS_WIDTH(1), kELCDIF_DataBus16Bit = LCDIF_CTRL_LCD_DATABUS_WIDTH(0), kELCDIF_DataBus18Bit = LCDIF_CTRL_LCD_DATABUS_WIDTH(2), kELCDIF_DataBus24Bit = LCDIF_CTRL_LCD_DATABUS_WIDTH(3) }
	The LCD data bus type. More...

enum	elcdif_as_pixel_format_t { kELCDIF_AsPixelFormatARGB8888 = 0x0, kELCDIF_AsPixelFormatRGB888 = 0x4, kELCDIF_AsPixelFormatARGB1555 = 0x8, kELCDIF_AsPixelFormatARGB4444 = 0x9, kELCDIF_AsPixelFormatRGB555 = 0xC, kELCDIF_AsPixelFormatRGB444 = 0xD, kELCDIF_AsPixelFormatRGB565 = 0xE }
	eLCDIF alpha surface pixel format. More...

enum	elcdif_alpha_mode_t { kELCDIF_AlphaEmbedded, kELCDIF_AlphaOverride, kELCDIF_AlphaMultiply, kELCDIF_AlphaRop }
	eLCDIF alpha mode during blending. More...

enum	elcdif_rop_mode_t { kELCDIF_RopMaskAs = 0x0, kELCDIF_RopMaskNotAs = 0x1, kELCDIF_RopMaskAsNot = 0x2, kELCDIF_RopMergeAs = 0x3, kELCDIF_RopMergeNotAs = 0x4, kELCDIF_RopMergeAsNot = 0x5, kELCDIF_RopNotCopyAs = 0x6, kELCDIF_RopNot = 0x7, kELCDIF_RopNotMaskAs = 0x8, kELCDIF_RopNotMergeAs = 0x9, kELCDIF_RopXorAs = 0xA, kELCDIF_RopNotXorAs = 0xB }
	eLCDIF ROP mode during blending. More...

enum	elcdif_lut_t { kELCDIF_Lut0 = 0, kELCDIF_Lut1 }
	eLCDIF LUT More...

Driver version
#define	FSL_ELCDIF_DRIVER_VERSION (MAKE_VERSION(2, 0, 2))
	eLCDIF driver version

eLCDIF initialization and de-initialization
void	ELCDIF_RgbModeInit (LCDIF_Type base, const elcdif_rgb_mode_config_t config)
	Initializes the eLCDIF to work in RGB mode (DOTCLK mode). More...

void	ELCDIF_RgbModeGetDefaultConfig (elcdif_rgb_mode_config_t *config)
	Gets the eLCDIF default configuration structure for RGB (DOTCLK) mode. More...

void	ELCDIF_Deinit (LCDIF_Type *base)
	Deinitializes the eLCDIF peripheral. More...

Module operation
void	ELCDIF_RgbModeSetPixelFormat (LCDIF_Type *base, elcdif_pixel_format_t pixelFormat)
	Set the pixel format in RGB (DOTCLK) mode. More...

static void	ELCDIF_RgbModeStart (LCDIF_Type *base)
	Start to display in RGB (DOTCLK) mode. More...

void	ELCDIF_RgbModeStop (LCDIF_Type *base)
	Stop display in RGB (DOTCLK) mode and wait until finished. More...

static void	ELCDIF_SetNextBufferAddr (LCDIF_Type *base, uint32_t bufferAddr)
	Set the next frame buffer address to display. More...

void	ELCDIF_Reset (LCDIF_Type *base)
	Reset the eLCDIF peripheral. More...

static void	ELCDIF_EnablePxpHandShake (LCDIF_Type *base, bool enable)
	Enable or disable the hand shake with PXP. More...

Status
static uint32_t	ELCDIF_GetCrcValue (LCDIF_Type *base)
	Get the CRC value of the frame sent out. More...

static uint32_t	ELCDIF_GetBusMasterErrorAddr (LCDIF_Type *base)
	Get the bus master error virtual address. More...

static uint32_t	ELCDIF_GetStatus (LCDIF_Type *base)
	Get the eLCDIF status. More...

static uint32_t	ELCDIF_GetLFifoCount (LCDIF_Type *base)
	Get current count in Latency buffer (LFIFO). More...

Interrupts
static void	ELCDIF_EnableInterrupts (LCDIF_Type *base, uint32_t mask)
	Enables eLCDIF interrupt requests. More...

static void	ELCDIF_DisableInterrupts (LCDIF_Type *base, uint32_t mask)
	Disables eLCDIF interrupt requests. More...

static uint32_t	ELCDIF_GetInterruptStatus (LCDIF_Type *base)
	Get eLCDIF interrupt peding status. More...

static void	ELCDIF_ClearInterruptStatus (LCDIF_Type *base, uint32_t mask)
	Clear eLCDIF interrupt peding status. More...

LUT
The Lookup Table (LUT) is used to expand the 8 bits pixel to 24 bits pixel before output to external displayer. There are two 256x24 bits LUT memory in LCDIF, the LSB of frame buffer address determins which memory to use.
static void	ELCDIF_EnableLut (LCDIF_Type *base, bool enable)
	Enable or disable the LUT. More...

status_t	ELCDIF_UpdateLut (LCDIF_Type base, elcdif_lut_t lut, uint16_t startIndex, const uint32_t lutData, uint16_t count)
	Load the LUT value. More...

Data Structure Documentation

struct elcdif_pixel_format_reg_t

These register bits control the pixel format:

CTRL[DATA_FORMAT_24_BIT]
CTRL[DATA_FORMAT_18_BIT]
CTRL[DATA_FORMAT_16_BIT]
CTRL[WORD_LENGTH]
CTRL1[BYTE_PACKING_FORMAT]

Data Fields
uint32_t	regCtrl
	Value of register CTRL. More...

uint32_t	regCtrl1
	Value of register CTRL1. More...

Field Documentation

uint32_t elcdif_pixel_format_reg_t::regCtrl

uint32_t elcdif_pixel_format_reg_t::regCtrl1

struct elcdif_rgb_mode_config_t

Data Fields
uint16_t	panelWidth
	Display panel width, pixels per line. More...

uint16_t	panelHeight
	Display panel height, how many lines per panel. More...

uint8_t	hsw
	HSYNC pulse width. More...

uint8_t	hfp
	Horizontal front porch. More...

uint8_t	hbp
	Horizontal back porch. More...

uint8_t	vsw
	VSYNC pulse width. More...

uint8_t	vfp
	Vrtical front porch. More...

uint8_t	vbp
	Vertical back porch. More...

uint32_t	polarityFlags
	OR'ed value of _elcdif_polarity_flags, used to contol the signal polarity. More...

uint32_t	bufferAddr
	Frame buffer address. More...

elcdif_pixel_format_t	pixelFormat
	Pixel format. More...

elcdif_lcd_data_bus_t	dataBus
	LCD data bus. More...

Field Documentation

uint16_t elcdif_rgb_mode_config_t::panelWidth

uint16_t elcdif_rgb_mode_config_t::panelHeight

uint8_t elcdif_rgb_mode_config_t::hsw

uint8_t elcdif_rgb_mode_config_t::hfp

uint8_t elcdif_rgb_mode_config_t::hbp

uint8_t elcdif_rgb_mode_config_t::vsw

uint8_t elcdif_rgb_mode_config_t::vfp

uint8_t elcdif_rgb_mode_config_t::vbp

uint32_t elcdif_rgb_mode_config_t::polarityFlags

uint32_t elcdif_rgb_mode_config_t::bufferAddr

elcdif_pixel_format_t elcdif_rgb_mode_config_t::pixelFormat

elcdif_lcd_data_bus_t elcdif_rgb_mode_config_t::dataBus

struct elcdif_as_buffer_config_t

Data Fields
uint32_t	bufferAddr
	Buffer address. More...

elcdif_as_pixel_format_t	pixelFormat
	Pixel format. More...

Field Documentation

uint32_t elcdif_as_buffer_config_t::bufferAddr

elcdif_as_pixel_format_t elcdif_as_buffer_config_t::pixelFormat

struct elcdif_as_blend_config_t

Data Fields
uint8_t	alpha
	User defined alpha value, only used when alphaMode is kELCDIF_AlphaOverride or kELCDIF_AlphaRop. More...

bool	invertAlpha
	Set true to invert the alpha. More...

elcdif_alpha_mode_t	alphaMode
	Alpha mode. More...

elcdif_rop_mode_t	ropMode
	ROP mode, only valid when alphaMode is kELCDIF_AlphaRop. More...

Field Documentation

uint8_t elcdif_as_blend_config_t::alpha

bool elcdif_as_blend_config_t::invertAlpha

elcdif_alpha_mode_t elcdif_as_blend_config_t::alphaMode

elcdif_rop_mode_t elcdif_as_blend_config_t::ropMode

Enumeration Type Documentation

enum _elcdif_polarity_flags

Enumerator
kELCDIF_VsyncActiveLow	VSYNC active low.
kELCDIF_VsyncActiveHigh	VSYNC active high.
kELCDIF_HsyncActiveLow	HSYNC active low.
kELCDIF_HsyncActiveHigh	HSYNC active high.
kELCDIF_DataEnableActiveLow	Data enable line active low.
kELCDIF_DataEnableActiveHigh	Data enable line active high.
kELCDIF_DriveDataOnFallingClkEdge	Drive data on falling clock edge, capture data on rising clock edge.
kELCDIF_DriveDataOnRisingClkEdge	Drive data on falling clock edge, capture data on rising clock edge.

enum _elcdif_interrupt_enable

Enumerator
kELCDIF_BusMasterErrorInterruptEnable	Bus master error interrupt.
kELCDIF_TxFifoOverflowInterruptEnable	TXFIFO overflow interrupt.
kELCDIF_TxFifoUnderflowInterruptEnable	TXFIFO underflow interrupt.
kELCDIF_CurFrameDoneInterruptEnable	Interrupt when hardware enters vertical blanking state.
kELCDIF_VsyncEdgeInterruptEnable	Interrupt when hardware encounters VSYNC edge.

enum _elcdif_interrupt_flags

Enumerator
kELCDIF_BusMasterError	Bus master error interrupt.
kELCDIF_TxFifoOverflow	TXFIFO overflow interrupt.
kELCDIF_TxFifoUnderflow	TXFIFO underflow interrupt.
kELCDIF_CurFrameDone	Interrupt when hardware enters vertical blanking state.
kELCDIF_VsyncEdge	Interrupt when hardware encounters VSYNC edge.

enum _elcdif_status_flags

Enumerator
kELCDIF_LFifoFull	LFIFO full.
kELCDIF_LFifoEmpty	LFIFO empty.
kELCDIF_TxFifoFull	TXFIFO full.
kELCDIF_TxFifoEmpty	TXFIFO empty.

enum elcdif_pixel_format_t

This enumerator should be defined together with the array s_pixelFormatReg. To support new pixel format, enhance this enumerator and s_pixelFormatReg.

Enumerator
kELCDIF_PixelFormatRAW8	RAW 8 bit, four data use 32 bits.
kELCDIF_PixelFormatRGB565	RGB565, two pixel use 32 bits.
kELCDIF_PixelFormatRGB666	RGB666 unpacked, one pixel uses 32 bits, high byte unused, upper 2 bits of other bytes unused.
kELCDIF_PixelFormatXRGB8888	XRGB8888 unpacked, one pixel uses 32 bits, high byte unused.
kELCDIF_PixelFormatRGB888	RGB888 packed, one pixel uses 24 bits.

enum elcdif_lcd_data_bus_t

Enumerator
kELCDIF_DataBus8Bit	8-bit data bus.
kELCDIF_DataBus16Bit	16-bit data bus, support RGB565.
kELCDIF_DataBus18Bit	18-bit data bus, support RGB666.
kELCDIF_DataBus24Bit	24-bit data bus, support RGB888.

enum elcdif_as_pixel_format_t

Enumerator
kELCDIF_AsPixelFormatARGB8888	32-bit pixels with alpha.
kELCDIF_AsPixelFormatRGB888	32-bit pixels without alpha (unpacked 24-bit format)
kELCDIF_AsPixelFormatARGB1555	16-bit pixels with alpha.
kELCDIF_AsPixelFormatARGB4444	16-bit pixels with alpha.
kELCDIF_AsPixelFormatRGB555	16-bit pixels without alpha.
kELCDIF_AsPixelFormatRGB444	16-bit pixels without alpha.
kELCDIF_AsPixelFormatRGB565	16-bit pixels without alpha.

enum elcdif_alpha_mode_t

Enumerator
kELCDIF_AlphaEmbedded	The alpha surface pixel alpha value will be used for blend.
kELCDIF_AlphaOverride	The user defined alpha value will be used for blend directly.
kELCDIF_AlphaMultiply	The alpha surface pixel alpha value scaled the user defined alpha value will be used for blend, for example, pixel alpha set set to 200, user defined alpha set to 100, then the reault alpha is 200 * 100 / 255.
kELCDIF_AlphaRop	Raster operation.

enum elcdif_rop_mode_t

Explanation:

AS: Alpha surface
PS: Process surface
nAS: Alpha surface NOT value
nPS: Process surface NOT value

Enumerator
kELCDIF_RopMaskAs	AS AND PS.
kELCDIF_RopMaskNotAs	nAS AND PS.
kELCDIF_RopMaskAsNot	AS AND nPS.
kELCDIF_RopMergeAs	AS OR PS.
kELCDIF_RopMergeNotAs	nAS OR PS.
kELCDIF_RopMergeAsNot	AS OR nPS.
kELCDIF_RopNotCopyAs	nAS.
kELCDIF_RopNot	nPS.
kELCDIF_RopNotMaskAs	AS NAND PS.
kELCDIF_RopNotMergeAs	AS NOR PS.
kELCDIF_RopXorAs	AS XOR PS.
kELCDIF_RopNotXorAs	AS XNOR PS.

enum elcdif_lut_t

The Lookup Table (LUT) is used to expand the 8 bits pixel to 24 bits pixel before output to external displayer.

There are two 256x24 bits LUT memory in LCDIF, the LSB of frame buffer address determins which memory to use.

Enumerator
kELCDIF_Lut0	LUT 0.
kELCDIF_Lut1	LUT 1.

Function Documentation

void ELCDIF_RgbModeInit	(	LCDIF_Type *	base,
		const elcdif_rgb_mode_config_t *	config
	)

This function ungates the eLCDIF clock and configures the eLCDIF peripheral according to the configuration structure.

Parameters

base	eLCDIF peripheral base address.
config	Pointer to the configuration structure.

void ELCDIF_RgbModeGetDefaultConfig ( elcdif_rgb_mode_config_t * config )

This function sets the configuration structure to default values. The default configuration is set to the following values.

config->panelWidth = 480U;
config->panelHeight = 272U;
config->hsw = 41;
config->hfp = 4;
config->hbp = 8;
config->vsw = 10;
config->vfp = 4;
config->vbp = 2;
config->polarityFlags = kELCDIF_VsyncActiveLow |
                        kELCDIF_HsyncActiveLow |
                        kELCDIF_DataEnableActiveLow |
                        kELCDIF_DriveDataOnFallingClkEdge;
config->bufferAddr = 0U;
config->pixelFormat = kELCDIF_PixelFormatRGB888;
config->dataBus = kELCDIF_DataBus24Bit;

Parameters

config Pointer to the eLCDIF configuration structure.

void ELCDIF_Deinit ( LCDIF_Type * base )

Parameters

base	eLCDIF peripheral base address.

void ELCDIF_RgbModeSetPixelFormat	(	LCDIF_Type *	base,
		elcdif_pixel_format_t	pixelFormat
	)

Parameters

base	eLCDIF peripheral base address.
pixelFormat	The pixel format.

static void ELCDIF_RgbModeStart ( LCDIF_Type * base )

inlinestatic

Parameters

base	eLCDIF peripheral base address.

void ELCDIF_RgbModeStop ( LCDIF_Type * base )

Parameters

base	eLCDIF peripheral base address.

static void ELCDIF_SetNextBufferAddr	(	LCDIF_Type *	base,
		uint32_t	bufferAddr
	)

inlinestatic

Parameters

base	eLCDIF peripheral base address.
bufferAddr	The frame buffer address to set.

void ELCDIF_Reset ( LCDIF_Type * base )

Parameters

base	eLCDIF peripheral base address.

static void ELCDIF_EnablePxpHandShake	(	LCDIF_Type *	base,
		bool	enable
	)

inlinestatic

Parameters

base	eLCDIF peripheral base address.
enable	True to enable, false to disable.

static uint32_t ELCDIF_GetCrcValue ( LCDIF_Type * base )

inlinestatic

When a frame is sent complete (the interrupt kELCDIF_CurFrameDone assert), this function can be used to get the CRC value of the frame sent.

Parameters

base	eLCDIF peripheral base address.

Returns: The CRC value.

Note: The CRC value is dependent on the LCD_DATABUS_WIDTH.

static uint32_t ELCDIF_GetBusMasterErrorAddr ( LCDIF_Type * base )

inlinestatic

When bus master error occurs (the interrupt kELCDIF_BusMasterError assert), this function can get the virtual address at which the AXI master received an error response from the slave.

Parameters

base	eLCDIF peripheral base address.

Returns: The error virtual address.

static uint32_t ELCDIF_GetStatus ( LCDIF_Type * base )

inlinestatic

The status flags are returned as a mask value, application could check the corresponding bit. Example:

uint32_t statusFlags;
statusFlags = ELCDIF_GetStatus(LCDIF);
if (kELCDIF_LFifoFull & statusFlags)
{
}
if (kELCDIF_TxFifoEmpty & statusFlags)
{
}

Parameters

base	eLCDIF peripheral base address.

Returns: The mask value of status flags, it is OR'ed value of _elcdif_status_flags.

static uint32_t ELCDIF_GetLFifoCount ( LCDIF_Type * base )

inlinestatic

Parameters

base	eLCDIF peripheral base address.

Returns: The LFIFO current count

static void ELCDIF_EnableInterrupts	(	LCDIF_Type *	base,
		uint32_t	mask
	)

inlinestatic

Parameters

base	eLCDIF peripheral base address.
mask	interrupt source, OR'ed value of _elcdif_interrupt_enable.

static void ELCDIF_DisableInterrupts	(	LCDIF_Type *	base,
		uint32_t	mask
	)

inlinestatic

Parameters

base	eLCDIF peripheral base address.
mask	interrupt source, OR'ed value of _elcdif_interrupt_enable.

static uint32_t ELCDIF_GetInterruptStatus ( LCDIF_Type * base )

inlinestatic

Parameters

base	eLCDIF peripheral base address.

Returns: Interrupt pending status, OR'ed value of _elcdif_interrupt_flags.

static void ELCDIF_ClearInterruptStatus	(	LCDIF_Type *	base,
		uint32_t	mask
	)

inlinestatic

Parameters

base	eLCDIF peripheral base address.
mask	of the flags to clear, OR'ed value of _elcdif_interrupt_flags.

static void ELCDIF_EnableLut	(	LCDIF_Type *	base,
		bool	enable
	)

inlinestatic

Parameters

base	eLCDIF peripheral base address.
enable	True to enable, false to disable.

status_t ELCDIF_UpdateLut	(	LCDIF_Type *	base,
		elcdif_lut_t	lut,
		uint16_t	startIndex,
		const uint32_t *	lutData,
		uint16_t	count
	)

This function loads the LUT value to the specific LUT memory, user can specify the start entry index.

Parameters

base	eLCDIF peripheral base address.
lut	Which LUT to load.
startIndex	The start index of the LUT entry to update.
lutData	The LUT data to load.
count	Count of `lutData`.

Return values

kStatus_Success	Initialization success.
kStatus_InvalidArgument	Wrong argument.

Overview

Typical use case

Frame buffer update

Alpha surface

Data Structures

Enumerations

Driver version

eLCDIF initialization and de-initialization

Module operation

Status

Interrupts

LUT

Data Structure Documentation

Data Fields

Field Documentation

Data Fields

Field Documentation

Data Fields

Field Documentation

Data Fields

Field Documentation

Enumeration Type Documentation

Function Documentation