DHCOM Settings
The hardware settings are configured with the DHCOM settings binary-file stored in the flash memory. This allows you to customize the hardware-settings without recompiling the bootloader. The settings-binary contains the following configuration options:
Please note: Each row of the diagram is treated like a 32-bit unsigned integer value. Please consider that the memory layout is little endian.
Supported by
- U-Boot DH VERSION v1.11.0.1 or higher for iMX25
- U-Boot DH VERSION v0.7.0.0 or higher for AM35x
Create a customized settings-block
The hard way to create a settings binary is to use a hex-editor and create a file with the memory-layout as shown above.
The easy way is to use the DHCOM Settings.bin Generator. If you use this tool you don´t have to bother about the layout of the binary. You can edit your settings in a easy to understand GUI. This tool provides you additional help through tooltips which appear if you move the mouse-pointer over a input element. You don't have to start from scratch. So called configuration-files are available to load predefined configurations from a xml structure. It is possible to store your own settings in a configuration-file to reuse them later for another board.
System requirements to run the DHCOM Settings.bin Generator on your PC
- Microsoft Windows
- .NET Framework 2.0
Download
Here you can download the current version of the DHCOM Settings.bin Generator:
Available configuration-files:
Settings Block description:
| Settings Name: | Description: | Unit: |
|---|---|---|
| VALIDATION_ID | „DH“ | |
| DISPLAY_ID | unique ID of Display | |
| LENGTH | Length of the settings block | |
| X_RESOLUTION | Display x resolution | pixel |
| Y_RESOLUTION | Display y resolution | pixel |
| PIXEL_CLOCK | Pixel clock | kHz |
| LCD_CONFIG_FLAGS | LCD Configuration Register | see description |
| HSW | Horizontal synchronization pulse width | pixel clocks |
| VSW | Vertical synchronisation pulse width | line clocks |
| HFP | Horizontal front porch | pixel clocks |
| HBP | Horizontal back porch | pixel clocks |
| VFP | Vertical front porch | line clocks |
| VBP | Vertical back porch | line clocks |
| DATALINES | count of datalines | number of datalines |
| ACB | AC Bias frequency | |
| ACBI | AC Bias transitions per interrupt | |
| GPIO_DIR | DHCOM GPIO default direction register | see description |
| GPIO_STATE | DHCOM GPIO default state register | see description |
| HW_CONFIG_FLAGS | Hardware Configuration Register | see description |
Remark: How to choose a PIXEL_CLOCK:
DHCOM iMX25
The frequency of the clock-source for the pixel clock is 66.5 MHz. The divider has to be greater or equal 2. Only the following pixel clock frequencies are possible:
- 33.250MHz
- 22.167MHz
- 16.625MHz
- 13.300MHz
- 11.083MHz
- 9.500MHz
- 8.312MHz
- 7.389MHz
- 6.650MHz
- ...
Be aware of the fact if you choose a pixel-clock between two possible values the smaller value will be used.
DHCOM AM35
The clock-source of the pixel-clock runs with 432.0 MHz. The divider has to be greater or equal 1.
Be aware of the fact if you choose a pixel-clock between two possible values the smaller value will be used.
LCD_CONFIG_FLAGS description:
| Settings Name: | Description: | Unit: |
|---|---|---|
| IVS | Inverted Vertical Sync Pulse | 0 active high / 1 active low |
| IHS | Inverted Horizontal Sync | 0 active high / 1 active low |
| IPC | Inverted Pixel Clock | 0 Data is sampled on rising edge / 1 Data is sampled on falling edge |
| IOE | Inverted Output Enable | 0 active high / 1 active low |
| IDATA | Inverted Data | 0 active high / 1 active low |
| ACT_PAS | Active or passiv matrix display | 0 passiv / 1active |
| PWM_POL | PWM polarity | 0 low state backlight off and high state backlight on / 1 low state backlight on and high state backlight off |
| BL_EN_GPIO | Backlight enable GPIO number | 0 no backlight enable GPIO / 1 DHCOM GPIO_A / 2 DHCOM GPIO_B / … / 9 = DHCOM GPIO_I |
| IBL | Inverted Backlight Enable | 0 active high / 1 active low |
GPIO_DIR description:
| Settings Name: | Description: | Unit: |
|---|---|---|
| GPIO_A_DIR | DHCOM GPIO_A direction | 1 input / 0 output |
| GPIO_B_DIR | DHCOM GPIO_B direction | 1 input / 0 output |
| … | ||
| GPIO_I_DIR | DHCOM GPIO_I direction | 1 input / 0 output |
GPIO_STATE description:
| Settings Name: | Description: | Unit: |
|---|---|---|
| GPIO_A_STATE | DHCOM GPIO_A default state if dir = output | 1 high / 0 low |
| GPIO_B_STATE | DHCOM GPIO_B default state if dir = output | 1 high / 0 low |
| … | ||
| GPIO_I_STATE | DHCOM GPIO_I default state if dir = output | 1 high / 0 low |
HW_CONFIG_FLAGS description:
| Settings Name: | Description: | Unit: |
|---|---|---|
| SILENT_MODE | Disable Bootloader messages on FFUART | 0 enabled FFUART outputs / 1 disabled FFUART outputs |
| UPDATE_DEV | Configures auto update storage devices | 0b000000 All Update Medias disabled
0bxxxxx1 Update via MicroSD Slot 0bxxxx1x Update via SD/MMC Slot 0bxxx1xx Update via USB Host 1 0bxx1xxx Update via USB OTG 0bx1xxxx Update via USB Host 2 0b1xxxxx Update via Ethernet |
| LCD_MODE | Enable Bootloader messages on LCD Display | 1 enabled / 1 disabled |
| DIS_CON | Disable Bootloader console on FFUART | 0 console enabled / 1 console disabled |
