[Product Innovation]
Controller IC Is Gateway To Multiple, Secure A/V Sources
Multiple transport ports, plus a variety of demultiplexing and descrambling algorithms in a single IC, fulfill the requirements of personal video recorders and set-top boxes.
The TL8xx family of set-top box/personal video recorder (STB/PVR) controller ICs consist of single-chip, multiple-transport, descrambler/controller devices. Due to their array of on-board descramblers and demultiplexers (demuxes), they are highly versatile devices, well-suited to perform as gateways for the flow of secured and encrypted audio, video, and interactive data streams. These ICs may be used to manage arriving and departing data streams—into and out of set-top boxes, storage devices, digital TVs, PVRs—as well as home media servers that connect to broadband cable, satellite, terrestrial, and IP networks.
In particular, the ICs from TeraLogic Inc. of Mountain View, Calif., have been designed to address the needs resulting from the rise in demand for PVR designs. These systems enable live TV channels to be paused and manipulated in other ways. Examples of this manipulation are pause, record, fast forward, and rewind. New systems also enable picture-in-picture (PIP).
The STB/PVR controller IC is said to be the first IC with the integrated functions to serve as a gateway for smart-card controllers, IEEE-1394 interfaces, high-speed CPU bridge and memory controllers, PCI controllers, and other peripherals like hard-disk drives, UARTs, infrared (IR), and I2C. These capabilities are possible because the ICs bring together what in the past required many individual chips. In addition, the ICs act as gateways for the TV or STB by managing and controlling multiple transport systems.
Traditionally, a separate north bridge chip would interface to the CPU and the PCI bus. Another chip would perform the demux function. There also would be a descrambler chip, and at least one or more chips to supply the interfaces, such as IDE.
On board the STB/PVR controller ICs are a programmable transport layer RISC engine, disk controller, descramblers for secure transactions, and demuxes. In addition, the devices contain a set of descrambling technologies designed to address the conditional access (CA) systems in worldwide use today. Therefore, the ICs can process their encrypted transport streams, decrypting them by using one or more of the devices' on-board algorithms.
Included too is a flexible arrangement for switching between the descramblers, demuxes, and various ports. In fact, due to the multiplicity of access that it affords, the STB/PVR controller IC can be thought of as a large crossbar switch. By this feature, it becomes relatively easy to route data through the different demux and descrambling processing blocks. Because it also can simultaneously handle audio, video, and data streams, which are encrypted using various worldwide CA standards, these ICs can be considered a universal solution for CA.
Multiple Ports The extraordinary flexibility of the STB/PVR controller IC is largely due to its ability to receive and manage four transport stream ports (Fig. 1). This unusual arrangement enables the IC to offer low-cost, flexible solutions for PVR applications and PIP, or any other configuration where transport streams are arriving from different sources. Incidentally, the four transport stream I/Os are compatible with a multitude of standards, including ATSC, ARIB, DVB, and DirecTV.
As an example of another application, a configuration could include receiving streams from satellite, terrestrial, digital VCR, and a hard-disk drive, all in a single, low-cost system. Or by adding the STB/PVR controller IC to an existing design, a standard set-top box can be upgraded to include PVR functions, PIP, or other more advanced, revenue-generating features.
There are two unidirectional ports—T/S 1 (in) and T/S 2 (in). One is designed to receive either parallel or serial streams, but the second only handles serial streams. These two ports are what enable the reception and management of two streams simultaneously for configuring features like PIP or watch-and-record (where the multiple ports enable the viewer to watch the input from one port while recording the other).
The third port, T/S 3 (in and out), is bidirectional, enabling transport streams to be either read or written across bidirectional interfaces such as the IEEE-1394. This interface is rapidly becoming the de facto interdevice connection for various components in the digital home of the future. It may become a common interface in set-top boxes, although it's perceived as expensive.
Reprints
