minimum clock speed needed for lcd tft display pricelist

Low voltage differential signaling (LVDS, also known as OpenLDI) thin-film transistor (TFT) liquid crystal (LCD) displays typically have a specified resolution and minimum required clock frequency to meet desired resolution. Normally, you will find this information listed in the display data sheet and won’t need to perform any calculations.

However, if you do not yet have access to your display data sheet and only know what resolution you want your system to support, you can estimate what clock frequency you need and determine which serializer/deserializer (SerDes) is appropriate for your application.

%Blanking: The blanking period, or the percentage of time when active video is not being displayed. As shown in Figure 1, it is represented horizontally as horizontal pulse width (HPW), horizontal back porch (HBP) and horizontal front porch (HFP). It is also represented vertically as vertical pulse width (VPW), vertical back porch (VBP) and vertical front porch (VFP).

The values for these blanking parameters are listed in display data sheets. The total blanking period varies from 3% to 39%. If your system uses reduced blanking, then you can estimate %Blanking at 10%. If you are not sure what blanking period your system uses, estimate around 20% and above to be conservative.

Frame rate (or refresh rate):the frequency at which consecutive images (frames) are displayed, and is measured in hertz or frames per second (fps). 60Hz is the most common frame rate, but this value can vary from 24Hz to 70Hz.

Throughput is another metric that you can use to determine whether or not a device will support your desired display resolution. The throughput is the effective payload of video data, and is derived from the required pixel clock frequency and color depth of your system, as shown in Equation 2:

Color depth: For a first-generation SerDes like the SN65LVDS93A, color depth is typically 24-bit red-green-blue (RGB) or 18-bit RGB for single pixel in, single pixel out (SISO) applications, and 48-bit RGB or 36-bit RGB for dual pixel in, dual pixel out (DIDO) applications.

The color depth will determine how many LVDS data lanes your display requires. SerDes serialize data at a rate of 7x the pixel clock frequency on each LVDS data lane. If the color depth is 24-bit RGB, then you will need four LVDS data lanes (there are an additional four bits used for control, which brings the total bit count to 28 bits) and can use a SerDes like the SN65LVDS93A. If the color depth is 18-bit RGB, then you will need three LVDS data lanes (there are an additional 3 bits used for control, which brings the total bit count to 21 bits) and can use a SerDes like the SN74LVDS84A or the SN65LVDS93A.

If the color depth is 48-bit RGB, then you will need eight LVDS data lanes (there are an additional 8 bits used for control, which brings the total bit count to 56 bits) and will need to use a device like the DS90C387 or DS90C189-Q1, which can output as many as eight LVDS data lanes.

When calculating the throughput for DIDO applications, you need to calculate the throughput for the odd pixels and even pixels separately and then add them together. For example, for a 48-bit DIDO application, the total required throughput would be 2 x Pixel Clock x 24.

Since the color depth is 24-bit RGB, you will need four LVDS data lanes. The SN65LVDS93A is a good fit for this application, since it has a pixel clock frequency range of 10MHz to 135MHz. Additionally, the maximum throughput for each LVDS data lane on this device is 135 x 7 = 945Mbps. Because this device has four LVDS data lanes, the total maximum throughput is 945 x 4 = 3780Mbps, which is higher than the minimum required throughput.

So the minimum pixel clock frequency to support a 2048 x 1536 resolution display is 208MHz. However, since this is a 48-bit DIDO application, there are actually two clocks: the frequency is split between them. Each clock must have a frequency of at least 104MHz.

Since the color depth is 48-bit RGB, you will need eight LVDS data lanes. The DS90C387 and DS90C187 are a good fit for this application, since they have a pixel clock frequency range of 32.5MHz to 112MHz (the DS90C387) and 25MHz to 105MHz (the DS90C187) for each channel in DIDO applications. Thus, if you don’t have access to the display data sheet yet, you can still estimate the required pixel clock frequency and throughput to support your desired resolution. If the SerDes does not meet these parameters, data on the display may display incorrectly, or not display at all.

Since the display includes the Ilitek ILI9320 controller, then your interface requirements are much lower, as the microcontroller no longer has to interface directly with the TFT and instead only talks to the controller chip via a simple interface: either SPI, which takes six wires: RS, CS, CLK, MOSI, MISO and RESET. Or you can use an 8080-compatible parallel interface which takes 13 wires: an 8-bit data bus, and RS, CS, WR, RD and RESET. (There are options to use larger data-buses, up to 18 bits, but I don"t recommend that for a low end microcontroller.)

There are two optional interfaces in which the microcontroller generates all of the clock signals (VSYNC, HSYNC and DOTCLK); you don"t want to do that since it would require a high-end controller.

So just about any microcontroller will do, however you need to have enough flash memory to hold whatever static items you want to display; for example if you are going to be displaying text then you will need to allocate arrays to store bitmaps for whatever fonts you will use. Even a small font can take 60KB.

This is a small graphics library, specifically aimed at ATtiny microcontrollers, for the variety of small colour TFT displays available at low cost from suppliers like Adafruit, AliExpress, or Banggood:

It"s an updated version of my Tiny TFT Graphics Library. This latest version of the library supports both the classic ATtiny processors, such as the ATtiny85, and the new 0-series, 1-series, and 2-series ATtiny processors, such as the ATtiny402. Like the original library it allows you to plot points, draw lines, draw filled rectangles, and plot characters and text with an optional scale factor, in 16-bit colour.

This version adds the ability to plot outline rectanges, and outline and filled circles. I"ve included demo curve-plotting and histogram-plotting programs that adjust to fit any display.

This library supports TFT displays that use an SPI interface and require four pins to drive the display. This leaves one pin free on an 8-pin chip such as the ATtiny85 or ATtiny402. If you need more pins choose a larger chip, such as the ATtiny84 or ATtiny404.

Unlike my Compact TFT Graphics Library which uses standard Arduino SPI calls, this library uses direct I/O pin manipulations. This means that you can use any assignment of pins to the four I/O lines needed by the display, and makes it about twice as fast as one using SPI calls. I"ve also added support for some additional displays, so it now supports 16 different TFT displays.

On the classic ATtiny processors, such as the ATtiny85, the library uses the feature that you can toggle one or more bits in a port by writing to the PINB register; for example, to enable or disable the chip-select signal:

So provided you set all the pins to their disabled state at startup, the display routines can simply toggle the appropriate pins to enable or disable them.

The differences between each family of processors are handled by constants to define the pin assignments, and preprocessor macros to define the bit manipulations. If you use the circuits given below you won"t need to change anything, apart from specifying which display you"re using.

The ClearDisplay() routine has been optimised further by realising that we don"t need to keep setting the mosi bit, since to clear the display it is always zero, so the routine only needs to toggle the sck bit the appropriate number of times. I"m grateful to Thomas Scherer for suggesting this.

This library will work with displays based on the ST7735 which supports a maximum display size of 162x132, or the ST7789 and ILI9340/1 which support a maximum display size of 320x240. It includes parameters for the following colour TFT displays:

* These Adafruit displays conveniently all have the same edge-connector layout, so you can make a prototyping board or PCB that will take any of them, such as my Universal TFT Display Backpack.

Some of the AliExpress displays include a LDO 3.3V regulator, but not logic-level translation, so I recommend only interfacing them to a processor running from 3.3V.

The Adafruit displays all include an LDO 3.3V regulator and logic-level translation, so can be safely interfaced to processors powered from either 5V or 3.3V.

On the AliExpress red 160x128 display you need to connect the backlight pin to Vcc to turn it on. This doesn"t seem to be necessary with the other displays.

The library will probably support other TFT displays that use the same ST7735, ST7789, ILI9340/1 driver chips, but you may need to experiment with the parameters to get the image scaled and centered correctly.

The display needs to be connected to the microcontroller via four I/O lines: MOSI, SCK, CS, and DC. You can use any pins for these, but they should all be in the same port. You need to specify the port pin numbers of the pins you are using at the start of the Tiny TFT Graphics Library listing.

The 33kΩ pullup resistor from the display"s CS pin is optional; it is only needed on the AliExpress displays, and holds the chip select high to prevent the display from flickering while programming the ATtiny85.

The different displays are catered for by seven constants which specify the size of the display, the offsets relative to the area supported by the display driver, whether the display is inverted, the rotation value, and the order of the colours; for example:

By default the parameters give the correct orientation assuming you"re using the display with the header pins along the top, except in the case of the larger displays which have the header pins along the shorter edge, in which case the header pins are assumed to be on the left.

To check or adjust the values for each display you can run the TestChart() program, which draws a one-pixel border around the display area, and plots a red "F" to show the orientation:

The library will probably support other TFT displays that use the same driver chips, but you may need to experiment with the parameters to get the image scaled and centered correctly.

The foreground and background colours are defined by the two global variables fore and back. Initially these are set to White (0xFFFF) and Black (0) respectively:

The library includes basic graphics routines for plotting points and drawing lines. These work on a conventional coordinate system with the origin at lower left. For example, on the 80x160 display:

DrawRect() draws an outline rectangle andFillRect() draws a filled rectangle in the foreground colour with width w and height h, and the bottom left corner at the current drawing position:

DrawCircle() draws an outline circle andFillCircle() draws a filled circle in the foreground colour with radius radius, and the centre at the current drawing position:

By default the ATtiny85 runs at 1MHz. Choose Burn Bootloader to set the fuses for 8MHz operation, or your graphics will run rather slowly, then upload the program using an ISP (in-system programming) programmer such as Sparkfun"s Tiny AVR Programmer Board

Orient Display provides standard andhighly customized embedded display boards with the option of touch panel. The displays are embedded with software to save your valuable development time and cost. Your development time can be as long as several months or even years with little support and few crew members. It can also be as short as a few weeks or days with yourselves and Orient Display engineering team.

AGN series are designed for fast and reliable interactive interface for full-graphic display with touch panels. They are easy to develop, flexible, UI user friendly, and reliable. They save a lot of work on single-chip coding volume.

Orient Display has focused on ARM processor-related technologies for many years, and has accumulated rich experience in the development and implementation of ARM architecture products. While continuously launching development platforms and core board that meet the general needs of the market, it also addresses the individual project needs of customers.

Our Hardware team make prototypes in the shortest time according to your design ideas and requirements. We specialize in the design of cost-effective embedded ARM hardware solutions to meet your requirement for high reliability in a short development cycle.

Our Software team will help you customize all the functions of the cutting driver layer. As a complete solution provider for Linux, Android and WinCE in embedded systems, we can solve the end-to-end system-related problems of your products.

Select the Display kit that best suits your application requirements for microprocess, software and display. Orient Display kits come with ARM and Intel processors with various display sizes, touch panel technologies, software and interface options.

After fully discussion and evaluation with you, Orient Display engineering team can tailor make the Display Kit to fully fit your application requirements. Orient Display engineering team will work side by side with you to provide customization for firmware, hardware, software, mechanical design, and many more. Our engineering team will also fully test the customized embedded display prototypes to make sure they fully meet your original design target.

The above information can be overwhelming. Actually, we design a lot of embedded touch panels and LCD displays projects without being provided with so detailed information. Our engineers and customer service can quickly decide the parameters based on the customer’s applications. Please feel free to contact our engineers for details.

Sharp NEC Display Solutions incorporates both Sharp and NEC brands of display products. Including desktop, 4K and 8K UHD large format, video wall, dvLED, collaboration and interactive products, Sharp/NEC offers the widest portfolio of displays available. Understanding that every market and environment has unique requirements, Sharp/NEC prides itself on being your partner, delivering customized solutions to match your needs.

Chino, CA, March 1, 2021– Tianma, a leading global manufacturer of flat panel displays, has introduced a new product family of TFT LCD Modules (Thin Film Transistor - Liquid Crystal Display). The new P-Series (Professional Series) of standard products is dedicated to support the various requirements of the industrial and medical display markets. The first products in this new series will include XGA displays (8.4”, 10.4” and 12.1”), as well as wide-format products, from 7” WVGA to 13.3” FHD.

The P-Series display products will be available in three grades – Advanced, Basic and Entry – to better support the different customer needs in a variety of markets, including a range of features and product specifications around pixel density, viewing angle, contrast ratio, color gamut, black level uniformity, etc.

The Advanced grade is designed for demanding applications that call for more robust product specifications and performance requirements, including: high-contrast rating and longer-life LED (as in medical diagnostic equipment); high brightness and wide temperature range (for marine environments); special ruggedization to withstand high shock and vibration conditions (as encountered in construction vehicles).

The Basic grade of P-Series displays will offer a very good performance-to-cost ratio, meeting the standard specification and performance requirements of the market with typical brightness ratings and long-life LED backlights. The Entry level provides more cost-effective solutions for price-sensitive markets and applications.

P-Series modules will be available with Tianma’s PCAP (Projected Capacitive) touch technology, featuring Tianma designed and manufactured PCAP touch sensors. PCAP will be integrated in-house, with optical bonding or air gap (perimeter bond) construction. Wet & Glove touch sensing technology is available for high-end devices, and customized cover glass is optional.

All three grades of the P-Series family will be available in production for a minimum of five years (typically seven years or more) with a small minimum order quantity (MOQ). The P-Series will also be engineered around dedicated design rules to meet the particular requirements of the professional market. Further, the manufacture and assembly of the TFT-LCDs and PCAP sensors will all be done in-house, with industrial level driver support.

Samples from the initial P-Series product offering will be available starting Q1 2021. These first displays will include wide-format 7” WVGA, 10.6” WXGA, and 13.3” FHD products, in the Advanced high brightness versions. The first products with 4:3 format will all have XGA resolution and include both Advanced high brightness and Basic, in sizes 8.4”, 10.4” and 12.1”.

Regarding Tianma’s legacy Professional TFT LCD products, both standard TM-series and all NL-series modules will be promoted alongside the new P-series product offering. All of these products will remain in production and will continue to be fully supported.

Tianma America (TMA) is the leading provider of small- to medium-size display solutions to the Americas market utilizing advanced technologies and manufacturing resources of the Tianma Group Companies, which includes Tianma Micro-electronics (Shenzhen and Shanghai) and Tianma Japan, Ltd. (formerly known as NLT Technologies Ltd.), as well as manufacturing locations in Chengdu, Wuhan, Xiamen, Shenzhen and Shanghai China. Tianma America technologies can be found in smartphones, tablet PCs, industrial and medical instrumentation, wearables, home automation, household appliances, office equipment, and automotive and rear seat entertainment devices. Additional applications include test and measurement systems, instrumentation equipment, point-of-sale and ATM systems, gaming systems, global positioning systems, radio-frequency identification devices and barcode scanners.

Tianma America’s technology portfolio comprises TFT, LTPS, Oxide-TFT, AM-OLED, flexible, transparent, 3D, PCAP and In-cell/On-cell integrated touch. With a network of best-in-class distributors and value-added partners, Tianma America provides complete display module solutions for a broad base of customers and applications.

The content in this press release, including, but not limited to, product prices and specifications, is based on the information as of the date indicated on the document, but may be subject to change without prior notice.

I"m using an ILI9341-based LCD module, and the 4-wire SPI interface to communicate with it. According to the datasheet"s spec for this interface, I should be able to write at up to 1s/100ns(twc)=10Mhz, and read at up to 1s/150ns(trc)=6.66Mhz.

However, I am successfully writing and reading at 24Mhz! Not just for a simple test case, either. I"m doing complex graphics, mixed reads/writes for alpha blends, both 16-bit and 24-bit pixel writes, and so on - yet haven"t seen a single glitch. (Except those caused when I bump my dodgy old breadboard or jumper wires. That I"m using such poor connections, and it"s still working at this speed when not physically disturbed, make this even more amazing. The signal integrity must be horrible.)

In the past I"ve tried communicating with other complex SPI devices at speeds past their ratings, just to see what would happen. All started showing issues with modest increases, even when run at max Vdd. Yet I"m reading from this at 360% of its max rated speed! And I know of cases of others doing the same with their ILI9341-based LCD, as well.

Display technology has moved forward at light speed. For years, even sophisticated equipment made do with numeric and alphanumeric display technology, buttons, and LEDs.

With mass production, manufacturing refinements, and competition, thin film transistor (TFT) displays have drastically dropped in price while dramatically improving in performance. They are the de facto standard to the point where it is not only expected, it is demanded that any modern user interface be full color, brightly backlit, touch sensitive, and have high video speeds and a good viewing angle.

While simple low-cost 8-bit microcontrollers could easily handle the multiplexed 7- and 14-segment LED and alphanumeric LCD displays, the memory, processor speeds, and peripheral resources needed to drive a TFT are more than most modest microcontrollers can handle. As a result, dedicated controller chips, embedded modules, or faster, denser, and more streamlined processor architectures are needed.

This article looks at the factors that make a good MCU-to-TFT interface. This includes memory depths and architectures, paging, data transfer, signaling levels, interfaces, and on-chip peripherals to look for when selecting a microcontroller for a TFT application. It examines the TFT technology and present day product offerings, which your designs will need to drive. It also looks at some microcontrollers that provide native support for color TFT displays, looking at their techniques, features, trade-offs, and limitations. All displays, microcontrollers, drivers, inverters, and development tools mentioned in this article are available from Digi-Key Corporation.

TFT displays are a type of liquid crystal display in which the transistor controlling the pixel’s crystal is etched into a layer of amorphous silicon deposited on the glass (see Figure 1). As in an IC process, very small transistors are geometrically formed. The small size of the transistor means it will not significantly attenuate the light passing through.

The advantage of TFTs is that they are fast enough for video, provide a large and smooth color palette, and are pixel addressable through an electronic two-dimensional control matrix (see Figure 2). Most low-cost displays use an amorphous silicon crystal layer deposited onto the glass through a plasma-enhanced chemical vapor deposition.

Figure 2: Electronically, a stable VCOM reference is used throughout the display, and the gamma corrected drive voltage passes through each transistor.

Many versions of TFT technologies have led us to the modern displays. Early complaints like poor viewing angles, poor contrast, and poor backlighting have been addressed. Better light sources, diffusers, and polarizers make many displays very vivid, some even claiming to be daylight readable. Modern day techniques like in-plane switching improve viewing angles by making the crystals move in a parallel direction to the display plane instead of vertically. Better speeds and contrasts of modern display make them high performance for a fairly low cost.

Since TFTs are not emissive devices, they require backlighting. The most commonly deployed backlight technology is cold cathode florescent lighting (CCFL). These devices were designed, chosen, and used because they are very efficient and have very long lives. Typically, a CCFL bulb is rated as having in the ball park of a 50,000 hour ‘half-life. ’ This means that after 50,000 hours, it still works, but with half the intensity when it was new.

Modern displays, especially the smaller ones, have transitioned to white LED-based backlights. These are easier to manufacture, do not require the high voltage inverter which CCFL bulbs need, and are approaching a lower cost point compared to CCFL technology. Both CCFL and LED technologies will use diffuser layers inside the stackup to evenly distribute light. LED-based backlights may actually be side lights and use a lightpipe structure to distribute the light.

Transflective technology is steadily improving and is available in some TFT displays. This is where both a backlight and ambient external light are used to make the display visible. Sunlight may make it viewable, but generally speaking the transflective displays are less transmissive. This means that the backlight will have to be brighter (and require more power) to be on par with a purely transmissive display that requires a backlight all the time.

With TFT and most color display technologies, an individual pixel contains a red, a green, and a blue picture element (pel). The relative intensity of each color will determine the resulting blended color.

The relationship between the transmittance of light through a pixel and the applied voltage to liquid crystal pels is not linear. This means a standard linear DAC output will not match up with the standard RGB calibrations of standard monitors. In some applications, such as gaming and cell phones, this may not be important, since viewers of low resolution, washed out-video will hardly notice a slight shift in color. But for medical, instrumentation, and other more demanding types of applications, the gamma correction may be an important factor to consider when planning a design.

Either a gamma correction chip or a lookup table can be inserted into the data stream to do this correction. You should have a consistency of the LCD. Note that many LCD manufacturers do not make their own mother-glass. As such, they are subject to the slight variations from supplier to supplier. Unless you use a supplier that truly manufactures its own glass, this could be an issue later on down the road.

The color depth or color palette is dependent on the bit resolution used for each color. This typically ranges from an 18-bit interface consisting of 6 bits each for red, green and blue, to 24-bit interfaces using 8 bits per color.

Some displays will use dithering and alternating pixel colors to achieve a better blend of intermediate colors. Higher frame rates are also used since the persistence effect of phosphor-based displays does not carry over to LCDs. Determine the quality and smoothness of the display you will use. Not every frame rate control technique yields flicker- and jitter-free performance, especially at some resolutions. If you notice it, so will your customers and end users of your design.

The memory required to map the display image is key. While some micros will contain enough memory to hold a single page of display data (and not much else), you can see that a lot of memory is required for even a modest ¼ VGA display. This is more than what a typical microcontroller can house (see Table 1). As a result, an external bus interface to external RAM (SRAM, DRAM, or SDRAM) will be needed, especially if paging will be used.

Table 1: The memory required to map to a display is proportional to three times the square of the resolution because of the three color elements of each pixel.

Paging will allow better display quality since one page can be displayed while the next is being built in the background, then made live. This eliminates ghosting and image flicker when graphics are changing rapidly in effects like scrolling, moving sprites (graphical objects), color shade blending (for overlapping graphics as they move), etc.

A key feature when selecting a microcontroller for TFT interfacing is the DMA support. Multi-channel, flexible DMA will make a world of difference, especially when it comes to moving data between pages, character generator and rendering tables, animations and video. Along these lines, a preprogrammed and autonomous DMA functionality will allow you to refresh a display while the core microcontroller goes to sleep. This is a key power-reducing feature that can make a world of difference when operating from batteries.

Very high volume applications may justify using an OEM only for the glass and implementing your own control electronics from the glass up. This is especially true when designing a very small form factor device where the added flexibility of using your own PCB layout is critical to success. For those designing from the glass up, the primary interface will be drivers for the thin film transistors. The stable common voltage reference to which all pixels are referenced is key. This is called VCOM and several discrete and integrated solutions for generating a VCOM signal are available.

One effective solution is to use the National Semiconductor LMH6640MF/NOPB which is a rail-to-rail (up to 16 volts), voltage feedback, high output (up to 100 ma) amplifier optimized for TFT transistor driving. The fast 170 V/µS slew rate yields a 28 MHz full power bandwidth (at five volts) and its small SOT-23 package can be fit into tight spaces (see Figure 3).

The larger the panel, the more current will be required to operate the transistors. For larger panels, another contender is the Maxim MAX9550EZK+T which can drive up to 800 ma peaks up to 20 volts. It settles to within 0.1 percent in less than 2 µSec and features a soft start circuit to limit inrush current during startup. Note, the VCOM level is usually set between the upper voltage level and ground instead of being set to ground. This allows full scale alternating polarity to be driven to the pixels without the need for a negative power supply.

Also , the VCOM function and all its subtleties are often times integrated into more encompassing TFT driver chips like Texas Instruments’ LM8207MT/NOPB which combines an 18 channel gamma corrected driver with VCOM referencing buffer (see Figure 4). Note that the built-in VCOM buffer will allow a buffer tree to be created from a single reference for larger displays.

One approach to driving a TFT display without the need for a higher end processor is to use a discrete TFT controller chip that can be interfaced to a processor of lesser horsepower. An example is the Intersil TW8811-LD2-GR TFT controller chip (see Figure 5).

Aimed at a specific market segment, in this case automotive applications, the TW8811 combines control and even video standard (analog, RGB, S-Video, NTSC, PAL, and Secam) integration into a single chip controller. It supports and ties together different video sources to allow the same display to be used for navigation systems, engine displays, environmental control, in-car entertainment systems, backup cameras, etc.

The on-chip SDRAM interface provides the depth and cost-effective performance needed for displays up to WXGA resolutions, and the –40 to +85 degree temperature range makes this usable for a variety of harsh environment applications.

If a single microcontroller can control the task at hand as well as the embedded display, this is usually the most cost-effective solution. Most people will use a TFT module which already houses the VCOM, gamma correction, and TFT transistor drivers. As a result, the interface to the module is TTL, CMOS, or Low Voltage Differential Signaling (LVDS).

Thankfully, to help make TFT design tasks doable in a reasonable amount of time, the chip makers provide solutions targeted at display designs. Typically, these are higher-end, 32-bit, RISC-type processor architectures with streamlined peripherals and resources that handle both display-oriented and non-display-oriented functions such as communications, sensor interfacing, etc.

For example, the NXP Semiconductor LPC2478FBD208,551 is an ARM7™-based 72 MHz high- end microcontroller with LCD control up to 1024 x 768, 24-bit pixel resolutions. In addition to the very flexible DMA functionality, it incorporates USB, four UARTS, I²S, RTC, SD/MMC memory card, Ethernet, I²C, CAN, and more. It is a “Swiss Army Knife” processor that targets integrated, single processor type designs.

Devices like this need development environments and evaluation units and NXP is right there. The DK-57VTS-LPC2478 is a programmer’s development system that includes a 5.7 inch TFT with touch interface as well (see Figure 6). Note the 2M x 32 SDRAM for page buffering and graphic manipulations. NXP also offers the DK-57TS-LPC2478 which aims at sensor-based applications.

NXP Semiconductors is not alone by any means. Renesas Electronics America also provides processors with built-in support for TFTs. Take for example the DF2378RVFQ34V, an H8-based processor with advanced block transfer functionality built into the DMA. Like the NXP parts, it incorporates a slew of peripherals, Flash, memory interfaces, and I/O.

Not every processor needs to have a dedicated TFT interface to make it a viable candidate. For example, the TI TMS470R1B1MPGEA is a RISC-based 60 MHz ARM7 processor that can easily interface to a slew of TFT modules that are driven via a digital interface. While some modules need constant refreshing, others can be loaded with display data and generate all the timing and display data movement internally unburdening the host CPU. The CPU must be fast enough to keep up with any animations or video if this is the case.

TI also provides the very high-end Digital Media System-on-Chip (DMSoC) solutions like the DSP-based TMS320DM6446AZWTA. This is not your run-of-the-mill processor. Running at 513 MHz and housing 160 Kbytes of RAM, this 361-pin LFBGA device is part of the company’s high-end DaVinci™ series and is supported by several development platforms, one of them being the TMDSVDP6437 digital video EVM.

Many displays are readily available as test vehicles. Many of these can be directly driven with the processors mentioned here. Many other processors can also be used, like offerings from Atmel (AT91SAM9261B-CU) and STMicroelectronics (STM32F107VBT6).

No matter how many data sheets you read, what it boils down to is this: a display is a visual device. What will ultimately make the decision is how it looks when you display your screens on it.

Disclaimer: The opinions, beliefs, and viewpoints expressed by the various authors and/or forum participants on this website do not necessarily reflect the opinions, beliefs, and viewpoints of Digi-Key Electronics or official policies of Digi-Key Electronics.

Cisco MX700 and MX800 represent the performance line within Cisco’s portfolio of integrated video collaboration room systems. They combine beautiful design and powerful functionality into an all-in-one solution for medium-to-large meeting rooms. These multipurpose systems will transform your meeting room into a video collaboration hub - whether for connecting teams across the globe or for local meetings. The MX700 and MX800 feature dual LED monitors for a people-only or people-and-content experience. The MX800 is also available with a single LED monitor for a peopled-focused solution.

These room-based systems come standard with a built-in amplifier and speaker system for the ultimate high-fidelity sound. Premium resolution and dual display are also standard features on the MX700 and MX800. The intuitive Cisco Touch 10 control unit provides an ever so easy-to-use interface for both MX700 and MX800 systems.

Industry standards compliance lets the MX700 and MX800 support calls with any third party, standards-based system. And, as the industry’s only H.265-ready systems, the MX700 and MX800 lay the foundation for future bandwidth efficiencies made possible by the new standard. The systems now support cloud registration to Cisco Webexfor even faster and more cost effective deployment2.

●Simplified meeting-join experience with One Button to Push (OBTP) for scheduled devices in Cisco Webex meetings, whether registered on-prem or to the cloud

Table 2 lists the product specifications; Table 3 gives video and audio specifications; Table 4 gives network, security, and management specifications; and Table 5 gives ordering information for the Cisco MX700 and MX800.

●Eight microphones, 48V phantom powered, Euroblock connector, each with separate echo cancellers and noise reduction; all microphones can be set for balanced line level (2 Microphones included in base package)

●X.509 Digital Certificates (DER encoded binary); both DER and Base-64 formats are acceptable for the client and server certificates; certificates with a key size of 1024, 2048, and 4096 are supported

Cisco and our partners provide a broad portfolio of smart, personalized services and support that can help you realize the full business value of your Cisco video collaboration investment by increasing business agility and network availability. This portfolio of services accelerates business innovation by harnessing the network as a powerful business platform. For more information about these services, please visit: https://www.cisco.com/go/telepresenceservices.

Cisco Capital makes it easier to get the right technology to achieve your objectives, enable business transformation and help you stay competitive. We can help you reduce the total cost of ownership, conserve capital, and accelerate growth. In more than 100 countries, our flexible payment solutions can help you acquire hardware, software, services and complementary third-party equipment in easy, predictable payments.

This note will discuss the considerations made when choosing a microcontroller that will work for your display. A few requirements need to be met depending on the display’s features, interface, and size. These can also be determined by the embedded IC in the display. An overview of the considerations when choosing a microcontroller can be seen below. It should be noted that these items are separated for definition but may serve the same purpose and be interconnected in the ecosystem of the controller.

Application and display specific peripheral requirements. I2C, SPI, UART, Parallel, MIPI, LVDS, HDMI etc. Determines pin connections and required architecture of the device.

Flash and RAM memory requirements. Minimum frame buffer memory is dependent on the size andresolution of the display. Location of memory (external or internal) can restrict interface speed and must becompatible with the chosen interface.

Communication speed requirements defined by the interface and intended application. Refresh rateis determined on the size of the display and location of memory. This will indicate which processors arecompatible.

A displays embedded IC can offer resources such as internal RAM, clock generators and power control.This can save resources otherwise needed to be provided externally. Check the datasheet of the display’s ICcontroller for device function specifics.

Availability of resources for programming and debugging the microcontroller. Online resources andexampleprograms to leverage from can a lot of save time. Compatibility with a familiarprogramming environment isadditionally beneficial.

The interface selection is dependent on the intended application of the display. Each display has a different interface or different choices for a connection interface. For smaller displays a 3/4-wire serial interface would be sufficient. For larger display’s with high resolution a faster interface should be chosen. A parallel RGB interface is capable of high-speed data transmission however requires many pin connections. If the intended application for the display is video a MIPI, LVDS or HDMI connection would be a good choice.

The available memory of a microcontroller often becomes a highlighted issue when determining which microcontroller to select. The microcontroller needs a minimum amount of RAM to hold the frame buffer of the display. Even small displays require more RAM than a typical microcontroller possess. To verify that your microcontroller will have enough memory, it is important to calculate the frame buffer.

The minimum RAM required for the frame buffer in this example would then be 768kB. It is important to note that external RAM can be provided for the frame buffer if the microcontroller does not provide it internally. Clocking speed should be verified if using external RAM as the microcontroller cannot access external RAM as quickly. The clock frequency constrained by external RAM sometimes does not meet the minimum requirements of some very high-speed interfaces (ex. DSI-MIPI). Additionally, the display can contain some form of RAM depending on the IC controller inside the display. This can be verified on the specification sheet of the IC.

The speed of the microcontroller is heavily dependent on the interface used in the application. The minimum and maximum of the clock frequency is specified in the datasheet of the display and in the specification sheet of the display’s controller IC. The frame rate is typically around 50-60Hz, which is the median oscillation frequency to refresh the display to maintain an image. The display will often provide an internal high frequency clock that can be initialized to certain frequencies.

It is important to verify in the controller data sheet which resources are provided by the internal IC of the display. Some key information to look for would be: Does the display have sufficient RAM or does this need to be provided? Does the display have an internal oscillator for clock generation for the interface chosen? An additional graphics controller can be used to interface the display with the microcontroller to meet these requirements. Features like these can be utilized to avoid additional cost, space, and memory of your application.

After a brief consideration of intended application and interface of the display you can get some idea of which microcontroller processor and architecture you will need. There are a few different microcontroller processors to choose from. The main choices are ARM, AVR, PIC, and 8051. The difference between them is the bit size of the processor, 8-bit, 16-bit, 32-bit or 64-bit data . The data bit width is the amount of data that can be sent at a time. This determines the speed of data transfer and thus compatible applications and interfaces.

The AVR has an 8-bit processor and is a RISC type microcontroller. This type of processor is compatible with low speed interfaces (SPI, I2C) and smaller displays. A common AVR microcontroller board is the Arduino which has the embedded 8-bit ATMEL RISC processors. These processors are widely popular which provide the benefit of numerous online resources and availability. The Arduino processors (ATmega/SAM3X) are typically available in most microcontroller programming environments. Additionally, Arduino offers 32-bit AVR development boards which function closely to the ARM processors.

The AVR microcontrollers are constrained by the low frequency, internal memory availability and power costs. AVR’s cannot use external program memory but some may allow expansion of external SRAM. These microcontrollers alone would be incompatible for high frequency applications such as video, large displays, or capacitive touch panels.

The ARM microprocessors have a RISC architecture. They offer 32-bit or 64-bit processors and are great options for high speed interfaces (Parallel, LVDS, MIPI, HDMI) and high-resolution displays. Common ARM processors can be found from STMicroelectronics and Raspberry Pi. The most common version of the ARM processors is the “Microcontroller” Arm-M group which include the Cortex-M0 and Cortex-M4 series.

The ARM processors are compatible with most displays and connection interfaces. These microcontrollers have become increasingly popular, so the cost has become comparable between the ARM and the AVR types. These processors provide the speed, but it is recommended to verify the available RAM as these boards vary widely on included features.

The PIC architecture consists of 8, 16, and 32-bit processors developed by Microchip. The PIC 32-bit series of microcontrollers have been geared toward graphical embedded applications and there are a lot of resources online for these devices. There is a huge variety of PIC controllers which make them easily available. These microcontrollers are known for being low cost and are comparable to the ARM processors. The drawback of the PIC controllers is using Microchips programming environment, but this is based on preference.

The Intel MCS-51, more commonly known as the 8051 microcontrollers have a CISC architecture and an 8-bit processor. These processors differ in architecture from the previous and are programmed using a combination of C and assembly languages. The program memory is read only and does not have an on-board ISP. A special programming device is needed to rewrite the EEPROM or flash memory. These processors are typically small, low cost and low powered. This can make them favorable for battery powered devices. These processors are commonly used to initialize TFT displays and are combined with a graphics controller to provide the required resources such as RAM and clock frequency.

Development environments and online resources become considerably valuable when creating an application for your display. A brand new or uncommon microcontroller will have very few resources for reference. Even knowledgeable engineers can find frustrations with the manufacturers programming environments. There are many microcontroller choices that will support your display with similar and overlapping features. Choosing a microcontroller with an available FAQ, application notes or is accessible on a familiar programming platform can save a lot of time.

Buyers and others who are developing systems that incorporate FocusLCDs products (collectively, “Designers”) understand and agree that Designers remain responsible for using their independent analysis, evaluation and judgment in designing their applications and that Designers have full and exclusive responsibility to assure the safety of Designers" applications and compliance of their applications (and of all FocusLCDs products used in or for Designers’ applications) with all applicable regulations, laws and other applicable requirements.

Designer agrees that prior to using or distributing any applications that include FocusLCDs products, Designer will thoroughly test such applications and the functionality of such FocusLCDs products as used in such applications.

Footnotes* Returns: The 30-day return period is calculated from invoice date. Exceptions to Dell"s standard return policy still apply, and certain products are not eligible for return at any time. See dell.com/returnpolicy.

* Offers subject to change, not combinable with all other offers, while supplies last. Dell may impose a purchase quantity limit (for example, 5 units per order). Taxes, shipping, and other fees apply. Free shipping offer valid only in Continental U.S. (excludes Alaska and P.O. Box addresses). Offer not valid for Resellers. Dell reserves the right to cancel orders arising from pricing or other errors.

* Rewards 3% back excludes taxes and shipping. Rewards are issued to your online Dell Rewards Account (available via your Dell.com My Account) typically within 30 business days after your order’s ship date. Rewards expire in 90 days (except where prohibited by law). “Current rewards balance” amount may not reflect the most recent transactions. Check Dell.com My Account for your most up-to-date reward balance. Total rewards earned may not exceed $2,000 within a 3-month period. Outlet purchases do not qualify for rewards. Expedited Delivery not available on certain TVs, monitors, batteries and adapters, and is available in Continental (except Alaska) U.S. only. Other exceptions apply. Not valid for resellers and/or online auctions. Offers and rewards subject to change without notice, not combinable with all other offers. See Dell.com/rewardsfaq. $50 in bonus rewards for Dell Rewards Members who open a new Dell Preferred Account (DPA), or Dell Business Credit (DBC) account on or after 8/10/2022. $50 bonus rewards typically issued within 30 business days after DPA or DBC open date.

Dell Coupon Offer:Offer valid 12/9/2022 - 1/5/2023 7:00AM CST. Coupon is valid with select other offers but not with other coupons. Coupon is valid on select order codes. One-time use only. Offer does not apply to, and is not available with, systems or items purchased through refurbished items or spare parts. Purchase limit of one item per order. Not valid for resellers and/or online auctions. Dell reserves the right to cancel orders arising from pricing or other errors.

^DELL PREFERRED ACCOUNT (DPA): Offered to U.S. residents by WebBank, who determines qualifications for and terms of credit. Taxes, shipping, and other charges are extra and vary. Your Minimum Payment Due is the greater of either $20 or 3% of the New Balance shown on your billing statement (excluding any balance on a Planned Payment Purchase prior to its expiration date) rounded up to the next dollar, plus any Monthly Planned Payment Due, plus the sum of all past due amounts. Minimum Interest Charge is $2.00. Rates range from 19.99% - 29.99% variable APR, as of 2/3/2023, depending on creditworthiness. Dell and the Dell logo are trademarks of Dell Inc. Six- and twelve-months special financing offers have different minimum purchase requirements. See Dell.com/nointerestdisclosures for important financing details.

^DELL BUSINESS CREDIT (DBC):Offered to business customers by WebBank, who determines qualifications for and terms of credit. Taxes, shipping and other charges are extra and vary. The Total Minimum Payment Due is the greater of either $20 or 3% of the New Balance shown on the statement rounded up to the next dollar, plus all past due amounts. Dell and the Dell logo are trademarks of Dell Inc. Three-month special financing is available on select purchases (a minimum purchase may be required). See Dell.com/DBCDisclosures for full promotional conditions.

*Expedited Delivery: * Expedited Delivery not available on certain TVs, monitors, batteries and adapters, and is available in Continental (except Alaska) U.S. only. Other exceptions apply. Not valid for resellers and/or online auctions. Offers subject to change, not combinable with all other offers. See Dell.com/rewardsfaq.