Basic explanation of server high Performance computing theory

The main functions of handheld computers (HPC) include: Operation processing, data storage, input and output, communication and system extension five, the organic combination of software and hardware is necessary to fully realize these functions. With the operating system using Microsoft's Windows CE2.0, the hardware selected for the system design is limited and must support this operating system. In addition, the hardware must meet the requirements of Chinese processing. Because it is a handheld computer, in the overall volume, power consumption and in line with human-machine engineering requirements and so on must be given special consideration.

1. Operational processing: Running Windows CE requires a specific series of 32-bit processors, in addition to basic information processing functions, such as personal information Management (PIM), calculators, electronic dictionaries, maps and other database retrieval and graphical user interface needs, but also requires such as digital communications, handwriting recognition, artificial intelligence, The computational power of higher information processing requirements such as language input. For example, the V.34 software modem will cost about 15MIPS (Millions instruction/sec) operations, voice compression needs 20MIPS calculation. The processor designed for embedded applications is limited by the size and power consumption of the chip, and the simplified instruction structure (RISC) is used to simplify the chip structure, and the performance of the chip is greatly improved. Hitachi's newly launched SH4 processor has a 200MHz operating speed of 360MIPS. Currently, the vast majority of 32-bit RISC processors for HPC are based on Hitachi's SH3 or R3000 chips (such as Philips PR31700, NEC VR4101, etc.) that are core to the MIPS company (now SGI acquired), although Windows CE The 2.0 version began to support Intel's x86, Motorola's PowerPC and DEC's arm processors, but the market was still small and lacked a wealth of commodity software.

2. Data storage: Because HPC does not have a hard disk as an external memory, all software and data are placed in memory, with a greater demand for RAM and ROM capacity. The minimum configuration for Windows CE 2.0 is 2MB RAM and 4MB ROM; After the Chinese Windows CE comes out, the need for ROM will be larger, such as plus their own development of Chinese information input and output program, at least 8Mb capacity of ROM. Mask ROM and flash Memory (Flash) are two options, the former on a mass production cost will be very low, the latter can be updated online. Intel has produced a single 64-bit (Mbit) flash memory using innovative multi-bit storage unit technology, and AMD in the United States and Toshiba in Japan have produced 32Mbit flash chips for battery-driven.

3. Input and output: HPC input forms include pens (Stylus), voice, keystrokes, and keyboards. The pen input is made on the pressure sensitive touch screen (touchscreen), which is the most important input form. There are two purposes for speech input, one for voice recording, and another for speech recognition as text or command input. The key is set up for a key to obtain information to facilitate the use of non-professional users. The keyboard is a traditional computer input device, especially suitable for the input of foreign letters, but also desktop professional users are accustomed to the form of entry. With the increasing of HPC's handheld and the maturity of online character recognition, this type of input is not indispensable, and may be replaced by pen input and virtual (software) keyboard.

HPC output has LCD display and voice, respectively, corresponding to the human visual and auditory. Screen size for the prev VGA 640x240 dot matrix and ferment VGA 240x320 lattice, display the GUI environment text and graphics data. LCD has monochrome, grayscale and color three kinds, the price from low to high, monochrome LCD common 2-bit 4 levels of gray, color LCD is 8-bit 256 colors. The speech output can not only replay the input sound signal, but also output the speech synthesized by the text, providing the speech proofreading and the language learning function. In addition, automatic audio dialing, alarm clock time hint is also the basic application of voice output can be completed.

4. Data communication: Flexible, powerful communication ability to make up for the narrow machine box on the HPC limit, and desktop computer data Synchronization Update is HPC distinguished from the previous PDA one of the salient features. Using RS232 standard serial port and IrDA infrared interface can achieve the local contact between HPC and PC and HPC, and can complete data synchronization and Exchange and program loading and upgrade. Communication with the Internet and remote computers, as well as the transmission of e-mail, is based on a 33.6kbps V.34 modem, after all, analog phone lines are currently the most popular communication infrastructure. The channel codec and error correction calculation of modem can be realized by the main processor through software, and the system needs only a V.34 analog front-end interface chip, which eliminates the problem of the current too large (about 600mA) when used in the modem based on PCMCIA. In addition, can also configure the adaptive infrared function, a variety of different appliances to implement remote control.

5. System expansion and Upgrade: PCMCIA is the standard expansion interface of Windows CE, it can be plugged into the compact Flash memory card, Ethernet and digital camera and other special card equipment. Because the Windows CE 2.0 operating system and its required memory size change, it is necessary to consider the system upgrade possible, the removable memory card can protect itself and the user's investment. At the same time, when the operating system and basic software changes not very much should also be able to use the online upgrade method to update.

6. Power control: As a battery-powered handheld device, HPC on the Run (keyboard-based), Sleep or Standby (Standby) in a state of three states, by the processor itself or the program to adjust the system, the maximum possible extension of battery time to use. Selected devices are designed for low-power equipment, in the absence of access can automatically enter the sleep or standby state, otherwise must be in the circuit to make a special power-saving design. Windows CE 2.0 recommends that in the 2-bit 4 grayscale 320x240 LCD display, HPC with 2MB RAM and 2MB ROM can provide 15-20 hours of continuous normal operation with 2 normal fifth (AA) alkaline batteries, And there is a choice of AC adapter for data exchange and other high power consumption programs to run.

7. Chinese information support: U.S. Microsoft has developed a Chinese Windows CE operating system, we should mainly consider the hardware for the system with sufficient mask ROM or flash Memory. In addition to the storage space occupied by the Chinese operating system, we have to make room for our Chinese character input method, intelligent handwritten input method, Voice command recognition program and their database. On the input interface, A/D converter with a touch screen and a voice must have a high resolution to meet the precision of the recognition.