Tear Down: Handheld phone/PC offers full-size laptop features
A few key components step up to bat to play some big roles, without burning excess power.
Just when you thought you had every tool to perform a Tear Down, along comes a product with screws that befuddled my arsenal of screw drivers. To take apart the HTC Advantage X7500 PocketPC phone, I needed a Torx-3 screwdriver. Unfortunately, my set of Torx screwdrivers only went down to size 4.
Back to the subject at hand. To call the Advantage X7500 a PocketPC phone really doesn't do it justice. In reality, it's way more than a tri-band 3G/HSDPA and quad-band GSM/GPRS/EDGE phone.
It's much smaller than a laptop, more like a conventional PDA. But it offers much of the same functionality of the laptop. It gives you the ability to work on any Microsoft Office document, albeit on a less than full size keyboard. It's designed with a 5-in. (rather eye-pleasing) VGA touch-screen display, an 8-Gbyte hard drive, and a mini SD Card slot. The integrated GPS and TomTom Navigator 6 are also nice touches. HTC claims that the system gets "up to" 8 hrs. of battery life. It does that by paying close attention to power management, implementing various slow-down and shut-down modes.
The on-board 3.0 Mpixel camera combines with a second (VGA) camera, enabling the user to make video calls on a 3G network. Throw in the Wi-Fi and stereo Bluetooth 2.0 connections, and you can pretty much be connected any where, any time.
At the heart of the Advantage X7500 platform is an Intel XScale CPU, the PXA270. The graphics is driven by an ATI Imageon 2294 media processor (now part of the AMD portfolio). The 2294 IC handles parts of the audio and video processing functions related to the digital camera, camcorder, streaming video, and video telephony applications.
Chrontel's CH7013 is employed as the digital PC-to-TV encoder. It provides a universal digital input port to accept a pixel data stream from a compatible VGA controller and converts this directly into NTSC or PAL TV format, or at least that's what Chrontel claimed. Unfortunately, a conversion was required to display the data properly.
The CH7013's digital NTSC/PAL encoder offers a 9-bit DAC interface, an adaptive flicker filter, and a high-accuracy, low-jitter phase locked loop (PLL). All features are software programmable through a serial port, to enable a complete PC solution using a TV as the primary display, as is the case in the Advantage X7500.
Another significant piece of silicon in the computer is a CSSP based on an 8150 Eclipse II family of ultra low-power products from QuickLogic. Working in conjunction with the Chrontel TV-output device, the 8150 handles the required video manipulation. The CH7013 gets the LCD output from the Xscale processor. However, the TV encoder chip requires standard NTSC TV input. Because NTSC uses horizontal scan lines and LCDs use vertical scan lines, the LCD output must be converted to TV input. This conversion occurs in real time, where the address inputs are swapped so that the data displays correctly on a horizontal scan line chain.