These days, at least in the major product categories that are driving the industry forward (smartphones and tablets), there is no such thing as a digital chip or an analog chip. They are all mixed-signal devices.
Lip-Bu Tan, president and CEO of Cadence Design Systems, said this month in his DAC 2013 Vision talk (which I covered for EDN) that the smartphone and tablet platforms have given the semiconductor industry an incredible boost, the likes of which has never been seen before.
One common aspect to these device classes is that they contain many interfaces to peripherals and communications networks. Peripherals include cameras, touch screens, audio interfaces, and memory of many types (including external flash). For example, the CMOS sensor for a camera is likely to be in a separate chip from the main processing chip. This requires a high-speed interface capable of streaming high-definition video between them. Many types of communications are available, including WiFi, Bluetooth, GPS, 3G and 4G wireless, and wired connections such as USB. In addition, many internal protocols are used to move information around within the system.
Also, these devices have to use little power, since battery life is a primary factor in purchasing decisions for these devices. We are even seeing a previous-generation platform — the laptop — becoming a lot more power conscious these days, so that it can compete with the tablets.
We don't tend to think of reuse and IP when it comes to the analog space, but this is one area where standards are being set, interfaces are being defined, and things such as the physical layers (PHY) of many of these interfaces can be boiled down to just a few choices. That enables specialization and interchangeability. One layer that has been defined for the mobile market is M-PHY. This was defined by the Mobile Industry Processor Interface (MIPI) Alliance, which was established in 2003 to create interfaces and standards for the mobile world. The same PHY can be used for many interfaces and protocols, including UniPro, DigRF, JEDEC Universal Flash Storage, USB SuperSpeed InterChip, and even PCIe.
What makes this PHY so popular is that it defines multiple power modes, including hibernate, sleep, burst, stall, and high-speed burst states. Along with this flexibility in power comes a whole bunch of additional logic to control the transitions between states — functions that are primarily digital.
sleep, burst, stall, and high-speed burst states.
(Source: MIPI Alliance)
The state diagram was originally published by the MIPI Alliance for the 1.0 version of the specification that came out in 2009. It shows that this block cannot be considered just an analog or digital block. I think we will see more such setups. This is just one example of digital supporting better analog. Several techniques are emerging these days where the two are coming together to solve problems that neither one could do efficiently or effectively on its own.
The next product platform wave is already taking shape and will fuel an era of ubiquitous computing and communications. It has already received several tags, such as the Internet of Things (IoT). This era will require even closer cooperation between analog and digital. I will be looking at other examples of digital assisting analog in my blogs, but perhaps you have some views on the IoT. Are we ready for the smart fridge? Are we ready to deal everything and everyone to be tagged and tracked? How will we deal with the privacy issues that this type of information sharing will create?