FAQ

Inquiry sheet

Please provide all appropriate details on the inquiry sheet provided and send the sheet to a Seiko Epson sales representative.

Inquiry sheet EXCEL



  • Q1How can I calculate the minimum display memory size for my application?
  • APlease use following formula for calculation.
    VMem[kB] = (Width x Length x Color depth)/8/1024
    Unis
    Width: [pixel]
    Length: [pixel]
    Color depth: [bpp]
  • Q2Is it possible to use Epson LCD Controllers in automotive applications?
  • AThere are numerous Epson LCD Controllers that are specified from -40℃ to +85℃ and therefore fulfill automotive requirements. Please refer to the specific LCD Controller for details.
  • Q3Are Epson LCD Controllers compatible with each other when making re-designs?
  • ASoftware compatibility is maintained wherever possible, however additional features require new registers and associated settings. Package compatibility is also maintained wherever possible, however advances in geometry and package technology continue to allow us to offer smaller footprints.
  • Q4Is there any reference design for LCD Controllers available?
  • AThe schematics of evaluation boards are available and can be used as a reference design. Please download evaluation board user manual which contains evaluation board schematics from each LCD Controller products page on vdc.epson.com
  • Q5What kind of processor model types can be connected to Epson LCD Controllers?
  • AEpson LCD Controllers support generic asynchronous SRAM type interface such as Intel 80, Direct and InDirect 8 and 16-bit bus interfaces. In addition to this, some LCD Controllers supports serial interface. Each product differs in its support so please refer to the specific LCD Controller documentation for details.
  • Q6Can an Epson LCD controller connect to an 8-bit processor?
  • AThere are numerous LCD Controllers that have specific 8-bit bus interfaces and others that can be configured using external logic. Please refer to the specific LCD Controller documentation for details.
  • Q7What panel types can I connect to Epson LCD Controllers?
  • AEpson LCD Controllers have support for all of the major LCD panel types: STN, CSTN, TFT. Support varies across the product line so please refer to the specific LCD Controller documentation for details.
  • Q8The LCD TFT panel specification shows an 18-bit data bus, but the LCD controller can store data only as 16bpp (bit-per-pixel). Can I display 16bpp on an LCD TFT panel with 18-bit data bus?
  • AYes. The TFT panel data bus width is independent of the data stored in memory. The LCD controller will internally expand the number of bits stored the memory to match the LCD panel data bus width. In the above example, 16bpp will be expanded to 18bpp by duplicating the 2 msb's to the missing 2 lsb's of the 18-bit value. Please note that the number of colors is still determined by the bit-per-pixel format used to store a pixel in the memory, it will note change by the expansion to match the LCD panel data bus width.
  • Q9Can an Epson LCD Controller connect to a processor which does not have a WAIT input?
  • AThe LCD Controller product line provides support for a variety of CPU bus types including both WAIT and no WAIT options. Refer to the specific LCD Controller documentation for details.
  • Q10What functionality does RESET# have for LCD Controllers?
  • AUpon initial power-up, all internal registers are in an unknown state. A reset pulse is required to set all internal registers to their default state prior to any register programming.
  • Q11What power consumption does Epson specify for LCD controllers?
  • AEpson does not include power consumption in it's Hardware Specifications. The power consumption depends on various parameters like input clock, processor bus clock, bus activity, supply voltage, display modes, etc. Epson offers Application Notes showing power consumption values for different configurations which could be used as guidelines for the expected power consumption in a particular design.
  • Q12How are colors and grayscales for CSTN panels generated?
  • AEpson LCD Controllers use Frame Rate Modulation to generate up to 16 grayscales and up to 4096 colors. In addition dithering can be used to generate up to 256 grayscales and up to 65535 colors.
  • Q13How is the pixel data transferred to a LCD TFT panel?
  • AData stored in the frame buffer has an associated bits/pixel (e.g 16bpp). This data is then converted if necessary to match the TFT panel interface width (e.g 16bpp data is converted to 18-bit data width). This data is then transferred one pixel/clock as shown in the following diagram.
  • Q14What clock is necessary to run Epson LCD Controllers?
  • AThe input clock frequency requirements are all included in the Hardware Specification for each part and differ across the product line. If an LCD Controller has a built-in PLL, then typically a lower input clock source is sufficient as all internal clocks are driven by the PLL. If an LCD Controller does not contain a PLL, then a higher frequency input clock source is typically required as all of the internal clocks are generated from this single source. Please refer to the specific LCD Controller documentation for details.
  • Q15An existing design uses the S1D13305. What kind of replacement can Epson recommend?
  • AThe recommended replacement parts are the S1D13700 and the S1D13709, however specific project requirements need to be considered as another LCD Controller may be more suitable.
  • Q16Where can I find the value of the maximum allowed pixel clock?
  • AThe maximum pixel clock is determined by the LCD panel itself and not the LCD Controller. Please refer to the specific LCD panel documentation for details. If the LCD Controller supports the display resolution, then most likely there will be numerous Pixel clock frequencies to choose from depending on the desired refresh rate.
  • Q17What advantages does external LCD Controller have over embedded LCD Controller?
  • AEmbedded / internal LCD Controllers can be quite limiting with respect to display resolution, power down modes, color depths, available bandwidth and specialized features. They are typically included in a processor design as simply one of many peripherals and therefore no special care is taken in the design or feature set. Using an external LCD Controller is usually required to alleviate one of the above mentioned limitations. Higher resolutions are supported, overall system power can be reduced by allowing the processor to 'sleep' while the external LCD Controller maintains display refresh. Extensive display orientated features can be realized such as acceleration, windowing, higher color depths, simultaneous displays, etc.
  • Q18What kind of software support can Epson offer for its LCD Controllers?
  • AThere are WindowsCE, QNX and Linux Console drivers available for many Epson LCD Controllers.
  • Q19How can I display 16M colors on a VGA display?
  • AAlthough a display controller may be able to support 24bpp color (16M colors), the display resolution itself limits the number of simultaneous colors that can be displayed. A VGA display has 307200 individual pixels. In the example of a display controller storing 24bpp information, you can display 307200 unique colors out of a possible 16M.
  • Q20Some of your LCD Controllers support camera's, is the host processor necessary to handle camera data?
  • ANo. In all of our controllers that support CMOS/CCD camera's, the camera data is piped to the frame buffer. A region (Picture in Picture) within the overall frame buffer is configured for the camera data. The display refresh circuitry reads this data and displays it without any intervention from the host CPU.
  • Q21What kind of camera's do you support?
  • AWe support cameras with digital output only, including cameras with output complying with ITU-R-656. Depending on the specific controller we support multiple data formats: YUV 4:2:2, JPEG. Please refer to the spefic product documentation for details.
  • Q22Can I drive more than a one LCD panel with a single controller?
  • AYes. We have several products that support multiple LCD panels. For example, the S1D13719 can support 2 active panels with the following interfaces: RGB, Serial, Parallel.
  • Q23If I don't need to use all the clock inputs of an LCD controller, what shall I do with unused clock inputs?
  • AIf a clock input is not used in a design, it should be connected to ground, either directly or through a resistor. If the LCD controller has a crystal port and it is not used, then the input pin should be connected to ground, either directly or through a resistor, and the output pin should be left not connected.
  • Q24For the LCD controllers that support a crystal as a clock source, can I use a ceramic resonator instead of a crystal?
  • ANo, ceramic resonators can not be used instead of the crystals. The internal oscillator in the LCD controller, is not designed to work with a ceramic resonator.
  • Q25Are the inputs of a 3.3V LCD controller tolerant to 5V signals?
  • ANo. The inputs do not tolerate voltages higher than the IO supply voltage, so if the IO voltage is 3.3V, the LCD controller will not tolerate 5V signals. Please refer to the absolute maximum ratings for each product.
  • Q26If a block inside the LCD controller is not used in my design, can I leave the power pins supplying that block unconnected? For example I am using S1D13719 and I am not using the SD Card interface, so what shall I do with SIOVDD pins?
  • AAll power pins must be connected to a power supply in our LCD controllers, no power pin should be left not connected. Even if a particular block in the LCD controllers is not used, the power pin for that block can not be left floating, they should be connected to a power supply.
  • Q27Can I access the LCD controller memory at power up without initializing the LCD controller?
  • ANo. Our LCD controllers will be in power save mode at power up and the memory can not be accessed. You must put the LCD controller in normal operation before being able to access the memory.
  • Q28Where can I find sample code for the S1D13xxx?
  • AThe Epson web site has API, sample code and reference drivers for all controllers in the marketing channel. The sample code offered may vary depending on initial software requests. Sample code is updated from time to time so check back to the web site for the latest versions.
  • Q29We will be using the S1D13xxx in our upcoming design. Do you have a reference display driver for the ??? operating system?
  • AWhile we make every effort to support all our controllers across a variety of platforms, due to limited resources it is impossible to provide a custom driver for every controller and operating system platform combination. If the driver you require is not available, contact us and we can suggest the best starting point for developing a driver to suit your needs.
  • Q30Does Epson provide graphic or windowing libraries for the S1D13xxx?
  • ANo, this has never been our practice. There are many excellent third party libraries providing this functionality.
  • Q31Has your driver/software ever been compiled/used on the ??? platform?
  • AMost of our sample and reference code has been built and run only on Intel hardware platforms. Code not developed specifically for a particular operating system (i.e. Linux drivers) will have been built and run under Windows. We make every effort to ensure our reference code follows C programming standards so that it may be easily ported to other platforms.
  • Q32How do I configure the S1D13xxx for use with the ??? panel?
  • AThe S1D13xxxCFG utility is a tool to assist with configuring Epson display controllers for use with your specific hardware. After the fields of the CFG utility are filled with your specific hardware configuration, the CFG utility can generate a file containing register values explicit to your needs. If the Epson controller is installed in the machine the CFG utility is run on then the CFG utility can also be used to directly tweak register settings. This is particularly useful for obtaining precise panel configuration values. In addition to this, simple to use type panel setting tool is available for some LCD Controllers.
  • Q33We have been using CHIP-A from Epson but in the future we will be using CHIP-B. What changes, if any, do I have to make changes to my software to support the new controller?
  • AWhile many of our controllers support similar features or register layouts it is not usually possible to continue using your existing code base without some modification. The extent of the changes is dependent on the complexity of the controller and the differences between the old and new controllers. This is something that needs to be examined on a case by case basis.
  • Q34When I write data to display memory the image does not appear as I expected.
  • AHere are the most common image distortion situations.
    Colors are all wrong but otherwise the image appears correct. The two most likely culprits are either an incorrectly configured Look-Up Table or you are writing 16-bit data one byte at a time and using the wrong byte order.
    The image looks correct but is only displayed in one color. The Look-Up table is not filled with the correct values.
    Image appears with jaggy staircase effect.
    The controller line address offset (stride) is not the same as the line address offset your graphics routine is using. Image appears twice (on the top and the bottom of the display) or fuzzy. Likely cause is the controller is set to 16bpp and you are drawing at 8bpp.
    I write data to display memory and I see nothing the screen.
    • Can you in fact read/write to display memory an control registers? Try reading/writing control registers. You should be able to read the Product Information register but not be able to change the contents.
    • Is the area of display memory the area currently being displayed? As a quick test try filling all of display memory with one color and then with another color to see if the screen changes.
  • Q35Please introduce suitable LCD Controller for our feature requirement.
  • APlease refer to product selection guide page on following URL.
    http://vdc.epson.com/index.php?option=com_content&view=article&id=76&Itemid=572