SDI

Overview

This sample demonstrates the application of driving a ICNA3311 LCD panel through SDI interface of the LCDC peripheral.

Requirements

For requirements, please refer to the Requirements.

Wiring

Connect P3_6 to the Reset pin.
Connect P4_2 to D0 pin.
Connect P4_1 to D1 pin.
Connect P3_2 to D2 pin.
Connect P3_3 to D3 pin.
Connect P4_3 to CS pin.
Connect P4_0 to CLK pin.
Connect P0_5 to TE pin.

Configurations

The following parameter ABGR_color in function rtk_lcd_hal_init() can be modified to change the color displayed on LCD screen.

uint32_t ABGR_color = 0x0000FF00;
rtk_lcd_hal_rect_fill(0, 0, 280, 456, ABGR_color);

Current default value stands for pure green.

Building and Downloading

For building and downloading, please refer to the Building and Downloading.

Experimental Verification

Screen Refresh Successfully

The screen is refreshed with certain color determined in Configurations.

Code Overview

This section introduces the code and process description for initialization and corresponding function implementation in the sample.

Source Code Directory

The directories for project file and source code are as follows:

Project directory: sdk\samples\peripheral\lcdc\lcdc_qspi\proj
Source code directory: sdk\samples\peripheral\lcdc\lcdc_qspi\src

Initialization

The initialization process is included in rtk_lcd_hal_init().

Enable clock of LCDC, and select suitable clock source.

/* config LCD dev info */
RCC_PeriphClockCmd(APBPeriph_DISP, APBPeriph_DISP_CLOCK, ENABLE);

//from XTAL SOURCE = 40M
PERIBLKCTRL_PERI_CLK->u_324.BITS_324.disp_ck_en = 1;
PERIBLKCTRL_PERI_CLK->u_324.BITS_324.disp_func_en = 1;
PERIBLKCTRL_PERI_CLK->u_324.BITS_324.r_disp_mux_clk_cg_en = 1;

//From PLL1, SOURCE = 100M
PERIBLKCTRL_PERI_CLK->u_324.BITS_324.r_disp_div_en = 1;
PERIBLKCTRL_PERI_CLK->u_324.BITS_324.r_disp_clk_src_sel0 = 0; //pll1_peri(0) or pll2(1, pll2 = 160M)
PERIBLKCTRL_PERI_CLK->u_324.BITS_324.r_disp_clk_src_sel1 = 1; //pll(1) or xtal(0)
PERIBLKCTRL_PERI_CLK->u_324.BITS_324.r_disp_div_sel = 1; //div

Initialize all the pins to be used.

Pad_Config(LCD_QSPI_RST, PAD_PINMUX_MODE, PAD_IS_PWRON, PAD_PULL_UP, PAD_OUT_DISABLE, PAD_OUT_HIGH);
Pad_Config(LCD_QSPI_D0, PAD_PINMUX_MODE, PAD_IS_PWRON, PAD_PULL_UP, PAD_OUT_DISABLE, PAD_OUT_HIGH);
Pad_Config(LCD_QSPI_D1, PAD_PINMUX_MODE, PAD_IS_PWRON, PAD_PULL_UP, PAD_OUT_DISABLE, PAD_OUT_HIGH);
Pad_Config(LCD_QSPI_D2, PAD_PINMUX_MODE, PAD_IS_PWRON, PAD_PULL_UP, PAD_OUT_DISABLE, PAD_OUT_HIGH);
Pad_Config(LCD_QSPI_D3, PAD_PINMUX_MODE, PAD_IS_PWRON, PAD_PULL_UP, PAD_OUT_DISABLE, PAD_OUT_HIGH);
Pad_Config(LCD_QSPI_CS, PAD_PINMUX_MODE, PAD_IS_PWRON, PAD_PULL_UP, PAD_OUT_DISABLE, PAD_OUT_HIGH);
Pad_Config(LCD_QSPI_CLK, PAD_PINMUX_MODE, PAD_IS_PWRON, PAD_PULL_UP, PAD_OUT_DISABLE, PAD_OUT_HIGH);
Pad_Config(LCD_QSPI_TE, PAD_PINMUX_MODE, PAD_IS_PWRON, PAD_PULL_UP, PAD_OUT_DISABLE, PAD_OUT_HIGH);

Pad_Dedicated_Config(LCD_QSPI_RST, ENABLE);
Pad_Dedicated_Config(LCD_QSPI_D0, ENABLE);
Pad_Dedicated_Config(LCD_QSPI_D1, ENABLE);
Pad_Dedicated_Config(LCD_QSPI_D2, ENABLE);
Pad_Dedicated_Config(LCD_QSPI_D3, ENABLE);
Pad_Dedicated_Config(LCD_QSPI_CS, ENABLE);
Pad_Dedicated_Config(LCD_QSPI_CLK, ENABLE);
Pad_Dedicated_Config(LCD_QSPI_TE, ENABLE);

Determine input and output color format, and select SDI interface. Enable TE signal.

LCDC_InitTypeDef lcdc_init = {0};
lcdc_init.LCDC_Interface = LCDC_IF_DBIC;
lcdc_init.LCDC_GroupSel = 1;
lcdc_init.LCDC_PixelInputFormat = LCDC_INPUT_RGB565;
lcdc_init.LCDC_PixelOutputFormat = LCDC_OUTPUT_RGB565;
lcdc_init.LCDC_PixelBitSwap = LCDC_SWAP_BYPASS;
lcdc_init.LCDC_TeEn = ENABLE;
lcdc_init.LCDC_TePolarity = LCDC_TE_EDGE_FALLING;
lcdc_init.LCDC_TeInputMux = LCDC_TE_LCD_INPUT;
lcdc_init.LCDC_DmaThreshold = 112;
LCDC_Init(&lcdc_init);

Initialize SDI interface, select clock divider, polarity and phase.

LCDC_DBICCfgTypeDef dbic_init = {0};
dbic_init.DBIC_SPEED_SEL         = 1;
dbic_init.SCPOL                  = DBIC_SCPOL_LOW;
dbic_init.SCPH                   = DBIC_SCPH_1Edge;
DBIC_Init(&dbic_init);

Control Reset pin to finish LCD panel reset procedure.

LCDC_LCD_SET_RST(false);
platform_delay_ms(100);
LCDC_LCD_SET_RST(true);
platform_delay_ms(120);
LCDC_LCD_SET_RST(false);
platform_delay_ms(50);

Send command and data with basic SPI protocol, these commands and data should refer to LCD producer’s guide book.

incna3311_cmd_param1(0xFE, 0x00);
incna3311_cmd_param1(0xC4, 0x80);           /*set quad SPI mode*/
incna3311_cmd_param1(0x35, 0x00);           /*set tear on*/
incna3311_cmd_param1(0x51, 0xff);           /*write display brightness*/
incna3311_cmd_param1(0x53, 0x20);           /*write display ctrl ,dimming*/
incna3311_cmd_param1(0x63, 0xFF);           /*write HBM display brightness*/

Functional Implementation

Set Update Window

Function rtk_lcd_hal_set_window is used to set the window of screen that is to be updated. This example demonstrates a window starting from point (0,0) with a width of 280 and a height of 456:

Set the window by sending commands to LCD panel. Using the range of window to construct data packet together with command.

//Horizontal Range
data[0] = xStart >> 8;
data[1] = xStart & 0xff;
data[2] = xEnd >> 8;
data[3] = xEnd & 0xff;
incna3311_cmd_param4(0x2A, data);
//Vertical Range
data[0] = yStart >> 8;
data[1] = yStart & 0xff;
data[2] = yEnd >> 8;
data[3] = yEnd & 0xff;
incna3311_cmd_param4(0x2B, data);

Switch AXI mode of LCDC to LCDC_FW_MODE to allow writing modification to SDI by API LCDC_AXIMUXMode().

LCDC_AXIMUXMode(LCDC_FW_MODE);

Set data size, address and commands for frame data transmission, after which switch LCDC back to LCDC_HW_MODE.

DBIC_CmdLength(1);
DBIC_AddrLength(3);
DBIC_TX_NDF(len_byte);
/* must push cmd and address to handler before SDI enable */
LCDC_SPICCmd(0x32);
LCDC_SPICAddr(0x002c00);
LCDC_AXIMUXMode(LCDC_HW_MODE);

DMA Configurations

After SDI interface is initialized, DMA should also be initialized to enable data transmission. The procedure is demonstrated in rtk_lcd_hal_clear_screen.

Initialize DMA parameter, including data size, burst size and source increament, to transmit data to LCD panel through initialized SDI interface. In this sample, single block mode is used.

LCDC_DMA_InitTypeDef LCDC_DMA_InitStruct = {0};
LCDC_DMA_StructInit(&LCDC_DMA_InitStruct);
LCDC_DMA_InitStruct.LCDC_DMA_ChannelNum          = LCDC_DMA_CHANNEL_NUM;
LCDC_DMA_InitStruct.LCDC_DMA_DIR                 = LCDC_DMA_DIR_PeripheralToMemory;
LCDC_DMA_InitStruct.LCDC_DMA_SourceInc           = LCDC_DMA_SourceInc_Inc;
LCDC_DMA_InitStruct.LCDC_DMA_DestinationInc      = LCDC_DMA_DestinationInc_Fix;
LCDC_DMA_InitStruct.LCDC_DMA_SourceDataSize      = LCDC_DMA_DataSize_Word;
LCDC_DMA_InitStruct.LCDC_DMA_DestinationDataSize = LCDC_DMA_DataSize_Word;
LCDC_DMA_InitStruct.LCDC_DMA_SourceMsize         = LCDC_DMA_Msize_8;
LCDC_DMA_InitStruct.LCDC_DMA_DestinationMsize    = LCDC_DMA_Msize_8;
LCDC_DMA_Init(LCDC_DMA_CHANNEL_INDEX, &LCDC_DMA_InitStruct);

Data Transmission

After internal DMA is intialized, data transmission is prepared. The procedure is demonstrated in rtk_lcd_hal_clear_screen.

Determine how many pixels should be sent within each frame with API LCDC_SetTxPixelLen().

LCDC_SetTxPixelLen(280 * 456);

Let DMA start to transmit data to internal FIFO with LCDC_DmaCmd().

LCDC_DmaCmd(ENABLE);

Let LCDC start to transmit data from internal FIFO to selected interface by calling API LCDC_AutoWriteCmd().

LCDC_AutoWriteCmd(ENABLE);

Polling status of LCDC. After DMA and SDI return to idle status, disable LCDC function.

while ((LCDC_HANDLER->DMA_FIFO_CTRL & LCDC_DMA_ENABLE) != RESET);//wait dma idle
LCDC_HANDLER_OPERATE_CTR_t handler_reg_0x14;
do
{
    handler_reg_0x14.d32 = LCDC_HANDLER->OPERATE_CTR;
}
while (handler_reg_0x14.b.auto_write_start != RESET);
LCDC_Cmd(DISABLE);
LCDC_ClearDmaFifo();
LCDC_ClearTxPixelCnt();
LCDC_AXIMUXMode(LCDC_FW_MODE);