PXA series processor
In order to cooperate with Microsoft PocketPC 2002 systems, Intel released a Strongarm processor's Improved product of the Strongarm processor in 2002, and the biggest improvement in this series is to increase Performance and is fully compatible with old products. This series includes a PXA210 with a frequency of 200 MHz, and a PXA250 having a frequency of 400 MHz and its latest improvement model PXA255 (widened bus frequency). This series of processors have been widely used in the new generation of PocketPC2002 / 2003.
Advantages: Performance and versatility is good, there are currently some advanced features such as wireless local area network, universal serial bus, Bluetooth and other technologies. Moreover, the new processor has also been well unified, and the current PocketPC processor specification is available. What is more worthwhile is that the lower frequency PXA210 is still able to run stable when overclocking to 300 MHz.
Disadvantages: This processor will disconnect, even slightly lower than the old Strangarm processor in performance in the absence of software support. It can be seen that Intel is still quite more than the problem facing the handheld device processor.
Representative products: Compaq IPAQ 1910/20, IPAQ3970, Sony TG50, and Acer's N10 and many other models, and is applied to some smartphones systems.
Processor frequency
The processor cluster is an important technical parameter that measures the high low CPU performance of the handheld, almost all people use it as a reference value when purchasing. "Working frequency" is also known as "frequency", the higher the frequency, the faster the execution speed of the instruction, the shorter the execution time of the instruction, and the processing ability and efficiency of the information are high. Here to say that beginners is that the working frequency of the processor does not completely determines its performance, design methods, and operational environments, etc. are an important factor in performance. At present, there are currently 266MHz, 300MHz and 400MHz, which are used on mainstream handheld computers.
For most users, the CPU cluster is generally quite good at 266MHz, fully meets general business functions, and now the models of 200MHz in 200MHz in the market have also been favored by many consumers.
Memory RAM capacity
The RAM (Random Access Memory) is a random access memory, which is equivalent to the mobile storage on the PC, used to store and save data. It can read and write at any time, and RAM is usually a temporary storage medium (which can be used as system memory) as an operating system or other running program.
However, the RAM cannot retain data when the power is turned off, and if you need to save the data, you must write them into a long-term memory (such as a hard drive). Because of this, the RAM is sometimes referred to as "variable memory". RAM memory can be further divided into two categories: static RAM (SRAM) and Dynamic Memory (DRAM). Dram has a large number of main memory as a system due to its low unit capacity.
Display type
The quality of the handheld computer's liquid crystal display is not only related to the comfort of the handheld computer, but also an important aspect of the performance of the handheld computer. Currently, the liquid crystal of handheld computers is divided into manufacturing technology, transmissive, reflective and transflective (also known as semi-reflective, transflective). The current handheld computer is basically adopted. The latter two types of display, while the transmissive liquid crystal display belongs to the technology adopted by early PDA, which is less in the newly launched handheld computer.
Display resolution
Simply put, the resolution of the display refers to the ability of the display to resolve the image, the higher the resolution, the clearer the image displayed on the display. For example, the early Palm models have been used in monochrome 160 × 160 resolution, which represents 160 pixels in the cross section of the display screen. Color display is generally resolution of 240 × 320, 320 × 320 and many other. Data transfer interface
The handheld computer is a small portable digital device, which has the advantages of convenient carrying, powerful, but the storage capacity is not large, and the files in the handheld should be stored in the computer from time to time, which involves the problem with the computer connection. The data transfer interface is an interface between the handheld computer and other devices such as a personal computer. Uploading, data synchronization, etc. can be achieved with this interface PDA and other devices. PDA common data transfer interface has a USB interface, serial port, infrared interface, and Bluetooth interface.
Infrared interface
Infrared Interface is an English abbreviation for IRDA, which is an English abbreviation of Infrared Data Association (Infrared Data Standards Association). The IRDA infrared interface is an infrared wireless transmission protocol and a wireless transmission interface based on this protocol. A handheld-in-PC supports wirelessly wirelessly connects to IrDA's wireless connections to implement information resources. The infrared interface allows users to wirelessly communicate with the computer, but directional restrictions, two devices to connect should be aligned with each other, and can only be connected within 1 meter, too short, and only hundreds of transmission speeds. . Its advantage is that there are many electronic devices that are also equipped with infrared interface. If the general mainstream mobile phones are configured with infrared interfaces, but the computer can only support infrared lines. If the user wants to use the infrared interface, turn on the chassis, on the motherboard Add a piece of adapter. However, the laptop is mostly configured with an infrared interface.
Compared to RAM and ROM, the maximum difference between the two is that the data saved above after the power is powered off, and the ROM will not. The 4 ~ 8M RAM is enough for the general application. If the multimedia function is pursued, the 64M RAM capacity can only be considered basic requirements.
Memory ROM capacity
The ROM (Read Only Memory) is only reading memory, which is equivalent to the hard drive on the PC, used to store and save data. The ROM data cannot be updated casually, but it can be read at any time. Even if it is power-off, the ROM can also retain data. However, data can only be used after writing, so ROM is often used as the purpose of the storage operating system in the embedded system. The ROM size of the mainstream PDA on the market is now 64MB and 128MB.
Compared to RAM and ROM, the maximum difference between the two is that the data saved above after the power is powered off, and the ROM is not.
Bluetooth function
Bluetooth is a short-range wireless connection technology for replacing the use of cables or connecting on certain electronic devices. With the "Bluetooth" technique, it is possible to effectively simplify the communication between the mobile communication terminals such as the palm, laptop, and mobile phone, and can successfully simplify the communication between the above equipment and the Internet, thereby enabling these devices and the Internet Data transfer becomes more efficient and efficient. There are currently a lot of palms with Bluetooth function, I believe that with the gradual development of the handheld computer, the Bluetooth function will become a common function of the handheld computer. But at present, the price of Bluetooth features is more expensive.
The Bluetooth interface of the handheld is also wireless connection with the other equally Bluetooth interface with the Bluetooth interface. It has no directional limits, and the effective connection distance is 10 meters. The general transmission speed is 1m, and the rapid up to 10m is even faster. Advantage, but the electronic device that is currently configuring the Bluetooth interface is not a lot, which is a big gap with the penetration rate of the infrared interface. This is a regrettable place, but the computer without Bluetooth interface can achieve Bluetooth by adding Bluetooth adapters. Interface features, these Bluetooth adapters are generally USB interfaces, which can be used on the USB interface of the computer, and only the flash is small, and it is convenient than the data line. The application mode of Bluetooth technology on the handheld computer is shown. You can also write Email through the handheld, but also send it immediately. There is no external line with the PC connection, everything is transmitted by the Bluetooth device. In this way, write email with the palm on the plane. When the plane landed, you only need to open the phone, all information can be automatically sent through the Bluetooth device of the airport. With blue bud technology, your handheld can keep synchronization with the desktop system.
Original article: http://www.sdpda.com/Article_view.asp? Id = 133 & Page = 1
