Design Article
Comment
Max the Magnificent
I remember a few years ago when there was all of the hullabaloo saying ...
Display interface and power-saving challenges: The system designer perspective
Paul Karazuba, QuickLogic Corporation
12/6/2011 4:41 PM EST
It’s not easy to be a system designer. You’re often handed a high-level set of specifications and told ‘make this work.’ For example, when a new tablet or smartphone is architected, high-level specifications such as the processor and display used are often chosen by people who don’t necessarily examine how easily these components can be integrated together. Regardless of who has chosen these components, responsibility most often falls to the system engineer to solve these issues within the product’s cost, size, and design targets.
Let’s address three challenges system designers face today, and the options for solving them…
Display / processor mismatches
We’ve established that when a display and processor is chosen for a particular product, often those are chosen for their consumer value (speed of processor, size and resolution of display), rather than how easily or efficiently those components can interact with each other.
Frequently, both displays and processors support only a single video interface standard. This is done for cost reasons, as supporting multiple interfaces requires more silicon area and usually a longer design time. Typical video interface standards in the mobile market include MIPI, LVDS and RGB. Each of these standards has its own history and ‘reason for being’ in the mobile space:
The variety of interfaces available gives the processors and display manufacturers multiple options during their product design cycle. They’ll typically choose the best single interface for their product. However, this then creates a problem, because the single interface chosen by the manufacturer of the processor may not match the interface of the display manufacturer. Per usual, it’s now the system designer’s job to make this work.
The system designer is faced with a couple of options to solve this problem. First, change the processor or display to match the interface. This is generally not acceptable, as it could negatively affect customer-level product performance specifications, such as the processor speed becoming slower, or the display being smaller or having a lower resolution. Such changes can often make a product non-competitive in performance and/or cost.
The alternative to swapping components is to add an interface ‘bridge’ chip. These discrete chips perform the single bridging function, but unfortunately are often large in size (up to 14 x 14mm) and can consume significant power resources in systems that are already power-constrained.
The bridge chip option is normally chosen, as it represents the best way to maintain the high level specifications of the OEM product. However, it does add cost and power consumption to the system, along with consuming available PCB space for a single function chip.
Power consumption
One of the key selling points of mobile devices is battery life. Often, after a product is passed to system designers, they are told that it needs to support a certain amount of battery life. And again, it’s the system designer’s job to figure out how to make that happen.
The option exists of changing out components as mentioned before, but this is most often a non-starter due to product performance requirements. Generally the system designer is stuck with finding ways to reduce the power consumption of the system as-is without changing major components.
In a typical mobile design, the display will consume as much as 50% of the total power, with 30% being consumed by the processor and the remaining 20% by a mix of discrete chips, the OS, antennas, etc. With displays consuming the most amount of power, they are the ‘low hanging fruit’ that is most often targeted for power reduction.
The power consumption of a display is mostly linked to brightness—the brighter the display, the more power consumed. As a way to extend battery life, the system designer can modify the Auto Brightness curve in their design to conserve more power. However, when brightness is reduced, it has the side effect of decreasing the viewability of the display, especially in non-ideal viewing conditions. Carriers, as well as consumers, are more frequently demanding that products be usable in all environments.
Known display power savings technologies like CABC (Content Adaptive Backlight Control) are commonly used, but these technologies only operate with lower contrast content such as streamed video. While they can save 5-10% of system battery life, those power savings are entirely dependent on content, and not consistent across all mobile use cases. Additionally, CABC and CABC-like technologies do absolutely nothing to improve the viewing experience.
So, how does a system designer balance the need for battery life with the need for display viewability?
Embedding a Pico Projector
Like displays, embedded pico projectors require a display interface signal coming from the processor. And like displays, the standards must match.
So, when faced with embedding a pico projector into a smartphone, how does a system designer address a common situation where the processor has a single output (say, MIPI), and the on-board display supports one interface (say, again, MIPI) but the pico projector supports only a different interface (say RGB)?
One option is to change to a dual-display output processor. But, as before, this creates potential customer-level product performance issues that may not be acceptable to the OEM. The other option to solve this problem is to add a bridge chip, but as mentioned before, this adds cost and power consumption, along with consuming PCB space.
A solution for all of these challenges
QuickLogic has introduced a line of products called the ArcticLink III VX that solves all of these design issues. The product family features 13 distinct chips that perform interface display bridging, interface pass-through, and interface duplication and bridging, all featuring QuickLogic’s Visual Enhancement Engine HD+ (VEE HD+) display viewability enhancement technology and Display Power Optimizer HD+ (DPO HD+) power savings technology.
So how does the ArcticLink III VX solve these issues?
Display Processor Mismatches
The ArcticLink III VX devices support bridging of the popular RGB, MIPI, and LVDS interfaces in various processor/display configurations. By using these devices, OEMs can be assured that the display and processor of choice can be used regardless of interface. This also ensures that consumers will receive a ‘no compromise’ design that offers the best performance and user experience.
At 4.5 x 4.5mm, the devices are significantly smaller than existing display bridges, making them more space-efficient for inclusion in the smallest of form factors. Finally, unlike competing solutions, the ArcticLink III VX also includes viewability enhancement and power savings technologies on-chip.
Power Consumption
We spent a great deal of time earlier speaking about brightness versus viewing experience, and how typical display power reduction technologies may save some power, but will not improve the viewing experience. QuickLogic’s VEE HD+ and DPO HD+ is a polar opposite to all conventional ways of addressing this.
VEE HD+ technology, based on the iridix® core from Apical Limited, greatly enhances the viewability of mobile displays. VEE HD+ sits in the video path between the processor and display, and examines each pixel of each frame of data. By making use of the viewing environment data provided by the on-board ambient light sensor, VEE HD+ optimizes the viewability of the display content based on how the human eye would best see that content. With VEE HD+ processing, the user can expect their displays to be readily viewable in all lighting environments, including direct sunlight.
And the best part of VEE HD+? It’s sister technology, DPO HD+, is actually reducing display brightness during operation, significantly extending system battery life.
We mentioned earlier that display brightness and viewability are linked. While VEE HD+ significantly improves the viewability of the display, display brightness is actually reduced significantly, still providing the user a greatly improved viewing experience. DPO HD+ technology dynamically adapts display brightness based on both ambient lighting and content.
As always, the proof is in the pudding—and in this case, DPO has been OEM-proven to extend system battery life as much as 41%.
Embedding a Pico Projector
The ArcticLink III VX includes two silicon variants (the VX6 family) that allow for the easy embed of a pico projector. In these variants, a MIPI signal is accepted from the processor. The ArcticLink III VX6 devices then duplicates that single incoming MIPI signal into two separate outgoing signals, and further converts one of those to the RGB standard, while leaving the second MIPI. The VX6 devices then output both of the MIPI and RGB signals. This allows a standard processor to display content on both the embedded display and the pico projector without complicated routing and design, and without the use of a larger bridge chip. The VX6 also includes the VEE HD+ and DPO HD+ technologies, allowing greater viewability and system power savings.
Conclusion
The ArcticLink III VX series of products from QuickLogic offers solutions for three common problems faced by system designers (display – processor interface mismatches, extending system battery life, and embedding a pico projector) in a single, multi-function chip with distinct OEM and user experience advantages.
Plus, we’re trying to make the life of the system designer just a little bit easier!
About the author
Paul Karazuba joined QuickLogic in April of 2010 as the Senior Product Marketing Manager in charge of Display and Display Enhancement Technologies. Prior to joining QuickLogic, Paul served in several marketing and sales positions at Aptina, Foveon and PerkinElmer.
At Aptina, a CMOS image sensor manufacturer, Paul was the Segment Manager in charge of the computer industry, and then followed as the North American Sales and Business Manager, managing all customers and sales in North America. Prior to Aptina, he was the Marketing Manager for DLSR image sensor products at Foveon. Paul holds BS degrees in Marketing and Management from Manhattan College, New York.
If you found this article to be of interest, visit Programmable Logic Designline where you will find the latest and greatest design, technology, product, and news articles with regard to programmable logic devices of every flavor and size (FPGAs, CPLDs, CSSPs, PSoCs...).
Also, you can obtain a highlights update delivered directly to your inbox by signing up for my weekly newsletter – just Click Here to request this newsletter using the Manage Newsletters tab (if you aren't already a member you'll be asked to register, but it's free and painless so don't let that stop you [grin]).
Let’s address three challenges system designers face today, and the options for solving them…
Display / processor mismatches
We’ve established that when a display and processor is chosen for a particular product, often those are chosen for their consumer value (speed of processor, size and resolution of display), rather than how easily or efficiently those components can interact with each other.
Frequently, both displays and processors support only a single video interface standard. This is done for cost reasons, as supporting multiple interfaces requires more silicon area and usually a longer design time. Typical video interface standards in the mobile market include MIPI, LVDS and RGB. Each of these standards has its own history and ‘reason for being’ in the mobile space:
- MIPI is a mobile consortium-based standard that acts not only as a display interface, but also as a camera and other peripheral interfaces. MIPI is found on many smartphone-sized displays, as well as many smartphone and tablet processors.
- LVDS owes its presence to the fact that the larger displays found in tablets are often based on designs from manufacturers who have long supported the notebook computer space, where LVDS is a dominant interface. However, LVDS is rarely found on mobile-targeted processors.
- RGB is a legacy interface that has been used in feature phones and smartphones for many years, on both processors and displays.
The variety of interfaces available gives the processors and display manufacturers multiple options during their product design cycle. They’ll typically choose the best single interface for their product. However, this then creates a problem, because the single interface chosen by the manufacturer of the processor may not match the interface of the display manufacturer. Per usual, it’s now the system designer’s job to make this work.
The system designer is faced with a couple of options to solve this problem. First, change the processor or display to match the interface. This is generally not acceptable, as it could negatively affect customer-level product performance specifications, such as the processor speed becoming slower, or the display being smaller or having a lower resolution. Such changes can often make a product non-competitive in performance and/or cost.
The alternative to swapping components is to add an interface ‘bridge’ chip. These discrete chips perform the single bridging function, but unfortunately are often large in size (up to 14 x 14mm) and can consume significant power resources in systems that are already power-constrained.
The bridge chip option is normally chosen, as it represents the best way to maintain the high level specifications of the OEM product. However, it does add cost and power consumption to the system, along with consuming available PCB space for a single function chip.
Power consumption
One of the key selling points of mobile devices is battery life. Often, after a product is passed to system designers, they are told that it needs to support a certain amount of battery life. And again, it’s the system designer’s job to figure out how to make that happen.
The option exists of changing out components as mentioned before, but this is most often a non-starter due to product performance requirements. Generally the system designer is stuck with finding ways to reduce the power consumption of the system as-is without changing major components.
In a typical mobile design, the display will consume as much as 50% of the total power, with 30% being consumed by the processor and the remaining 20% by a mix of discrete chips, the OS, antennas, etc. With displays consuming the most amount of power, they are the ‘low hanging fruit’ that is most often targeted for power reduction.
The power consumption of a display is mostly linked to brightness—the brighter the display, the more power consumed. As a way to extend battery life, the system designer can modify the Auto Brightness curve in their design to conserve more power. However, when brightness is reduced, it has the side effect of decreasing the viewability of the display, especially in non-ideal viewing conditions. Carriers, as well as consumers, are more frequently demanding that products be usable in all environments.
Known display power savings technologies like CABC (Content Adaptive Backlight Control) are commonly used, but these technologies only operate with lower contrast content such as streamed video. While they can save 5-10% of system battery life, those power savings are entirely dependent on content, and not consistent across all mobile use cases. Additionally, CABC and CABC-like technologies do absolutely nothing to improve the viewing experience.
So, how does a system designer balance the need for battery life with the need for display viewability?
Embedding a Pico Projector
Like displays, embedded pico projectors require a display interface signal coming from the processor. And like displays, the standards must match.
So, when faced with embedding a pico projector into a smartphone, how does a system designer address a common situation where the processor has a single output (say, MIPI), and the on-board display supports one interface (say, again, MIPI) but the pico projector supports only a different interface (say RGB)?
One option is to change to a dual-display output processor. But, as before, this creates potential customer-level product performance issues that may not be acceptable to the OEM. The other option to solve this problem is to add a bridge chip, but as mentioned before, this adds cost and power consumption, along with consuming PCB space.
A solution for all of these challenges
QuickLogic has introduced a line of products called the ArcticLink III VX that solves all of these design issues. The product family features 13 distinct chips that perform interface display bridging, interface pass-through, and interface duplication and bridging, all featuring QuickLogic’s Visual Enhancement Engine HD+ (VEE HD+) display viewability enhancement technology and Display Power Optimizer HD+ (DPO HD+) power savings technology.
So how does the ArcticLink III VX solve these issues?
Display Processor Mismatches
The ArcticLink III VX devices support bridging of the popular RGB, MIPI, and LVDS interfaces in various processor/display configurations. By using these devices, OEMs can be assured that the display and processor of choice can be used regardless of interface. This also ensures that consumers will receive a ‘no compromise’ design that offers the best performance and user experience.
At 4.5 x 4.5mm, the devices are significantly smaller than existing display bridges, making them more space-efficient for inclusion in the smallest of form factors. Finally, unlike competing solutions, the ArcticLink III VX also includes viewability enhancement and power savings technologies on-chip.
Power Consumption
We spent a great deal of time earlier speaking about brightness versus viewing experience, and how typical display power reduction technologies may save some power, but will not improve the viewing experience. QuickLogic’s VEE HD+ and DPO HD+ is a polar opposite to all conventional ways of addressing this.
VEE HD+ technology, based on the iridix® core from Apical Limited, greatly enhances the viewability of mobile displays. VEE HD+ sits in the video path between the processor and display, and examines each pixel of each frame of data. By making use of the viewing environment data provided by the on-board ambient light sensor, VEE HD+ optimizes the viewability of the display content based on how the human eye would best see that content. With VEE HD+ processing, the user can expect their displays to be readily viewable in all lighting environments, including direct sunlight.
And the best part of VEE HD+? It’s sister technology, DPO HD+, is actually reducing display brightness during operation, significantly extending system battery life.
We mentioned earlier that display brightness and viewability are linked. While VEE HD+ significantly improves the viewability of the display, display brightness is actually reduced significantly, still providing the user a greatly improved viewing experience. DPO HD+ technology dynamically adapts display brightness based on both ambient lighting and content.
As always, the proof is in the pudding—and in this case, DPO has been OEM-proven to extend system battery life as much as 41%.
Embedding a Pico Projector
The ArcticLink III VX includes two silicon variants (the VX6 family) that allow for the easy embed of a pico projector. In these variants, a MIPI signal is accepted from the processor. The ArcticLink III VX6 devices then duplicates that single incoming MIPI signal into two separate outgoing signals, and further converts one of those to the RGB standard, while leaving the second MIPI. The VX6 devices then output both of the MIPI and RGB signals. This allows a standard processor to display content on both the embedded display and the pico projector without complicated routing and design, and without the use of a larger bridge chip. The VX6 also includes the VEE HD+ and DPO HD+ technologies, allowing greater viewability and system power savings.
Conclusion
The ArcticLink III VX series of products from QuickLogic offers solutions for three common problems faced by system designers (display – processor interface mismatches, extending system battery life, and embedding a pico projector) in a single, multi-function chip with distinct OEM and user experience advantages.
Plus, we’re trying to make the life of the system designer just a little bit easier!
About the author
Paul Karazuba joined QuickLogic in April of 2010 as the Senior Product Marketing Manager in charge of Display and Display Enhancement Technologies. Prior to joining QuickLogic, Paul served in several marketing and sales positions at Aptina, Foveon and PerkinElmer.At Aptina, a CMOS image sensor manufacturer, Paul was the Segment Manager in charge of the computer industry, and then followed as the North American Sales and Business Manager, managing all customers and sales in North America. Prior to Aptina, he was the Marketing Manager for DLSR image sensor products at Foveon. Paul holds BS degrees in Marketing and Management from Manhattan College, New York.
If you found this article to be of interest, visit Programmable Logic Designline where you will find the latest and greatest design, technology, product, and news articles with regard to programmable logic devices of every flavor and size (FPGAs, CPLDs, CSSPs, PSoCs...).
Also, you can obtain a highlights update delivered directly to your inbox by signing up for my weekly newsletter – just Click Here to request this newsletter using the Manage Newsletters tab (if you aren't already a member you'll be asked to register, but it's free and painless so don't let that stop you [grin]).
|
|
|
|
|
Navigate to related information
Max the Magnificent
12/6/2011 4:57 PM EST
I remember a few years ago when there was all of the hullabaloo saying "QuickLogic are getting out of FPGAs"...
...of course this was when they decided to stop making "vanilla flavor" FPGA fabric and instead concentrate on what they call CSSPs (Customer Specific Standard Parts), which offer a mix of programmable fabric with hard processing and communications cores and hardware accelerators.
I think they've "done good" with these parts -- I also think their VEE and DPO technologies are very interesting.
The bottom line is that I think QuickLogic are perfectly poised to play a major role in today's tablets and smartphones ... and also in the new units that we expect to see in the very near future ... I for one cannot wait to have a tablet computer that also includes a Pico Projector, and I think we will be seeing QuickLogic in there...
Sign in to Reply