【導(dǎo)讀】從無(wú)線電世界到單片機(jī)世界現(xiàn)代計(jì)算機(jī)技術(shù)的產(chǎn)業(yè)革命,將世界經(jīng)濟(jì)從資本經(jīng)濟(jì)帶入。稱嵌入式系統(tǒng)),而單片機(jī)是最典型,最廣泛,最普及的嵌入式系統(tǒng).一,無(wú)線電世界造就了。幾代英才在20世紀(jì)五六十年代,最具代表的先進(jìn)的電子技術(shù)就是無(wú)線電技術(shù),包括無(wú)線電。廣播,收音,無(wú)線通信(電報(bào)),業(yè)余無(wú)線電臺(tái),無(wú)線電定位,導(dǎo)航等遙測(cè),遙控,遙信技術(shù).早期就是。美妙的前景.電子科學(xué)開始形成了一門新興學(xué)科.無(wú)線電電子學(xué),無(wú)線通信開始了電子世界。從無(wú)線電發(fā)報(bào)到業(yè)余無(wú)線電臺(tái);從電話,電鈴到無(wú)線電操縱模型.無(wú)線電技術(shù)成為當(dāng)時(shí)青少年。到無(wú)線電遙控,遙測(cè),遙信電子系統(tǒng)制作,培養(yǎng)出了幾代科技英才.二,從無(wú)線電時(shí)代到電子。電視機(jī),洗衣機(jī),微波爐,電話,防盜系統(tǒng),空調(diào)機(jī)等.單片。機(jī)革新了原有電子系統(tǒng),如微波爐采用單片機(jī)控制后,可方便地進(jìn)行時(shí)鐘設(shè)置,程序記憶,動(dòng)了整個(gè)電子產(chǎn)業(yè)目前電子元器件產(chǎn)業(yè)除了微處理器,

　　

【正文】 e clock voltage shock. Low voltage and high voltage protection circuit attack can be used to prohibit the work of processor execution errors or enforcement action. Clock transition may reset the transient protection circuit will not damage the protected information. Power and clock transients transition effects in certain singleprocessor instruction decoding and execution. (4) probe This technology is directly exposed to chip connection, and then observe, manipulate, interfere with single chip to achieve the attack purpose. For convenience, these four people will attack techniques are divided into two categories is the intrusion type attack (physical attack), such attack requires destruction of package, then use semiconductor test equipment, microscopes and micropositioning device, in a special laboratory spend hours or even weeks to plete. All of the microprobe techniques are invasive type attack. The other three methods are noninvasive type attack, attack the MCU will not be physical damage. In some cases, noninvasivetype attacks are particularly dangerous, but because of noninvasive type attacks can usually be made and the necessary equipment to upgrade, so it is cheap. Most noninvasive type attack requires the attacker have a good knowledge of processors and software knowledge. In contrast, the invasive type of probe do not need too much of the initial attack of knowledge, and usually a set of similar technology available to deal with a wide range of products MCU general process of invasiontype attack Invasive type of attack is thrown off its first chip package. There are two ways to achieve this goal: the first one is pletely dissolved out chip package, exposed metal connections. The second is only removed to the top of the plastic package silicon core. The first method is the need to bind to the test fixture on the chip, using bind Taiwan to operate. The second method requires the attacker in addition to a certain degree of knowledge and necessary skills, but also the wisdom and patience, but operate relatively easy. Above the plastic chips can be opened with a knife, epoxy around the chip can be eroded by concentrated nitric acid. Hot concentrated nitric acid will dissolve out without affecting the chip, chip packaging and connection. This process usually very dry conditions, because the presence of water may erode the aluminum wire connections have been exposed. Then, in ultrasonic cleaning of the pool first chip with acetone to remove residual nitric acid, then washed with water to remove salt and dried. No ultrasound pool, are generally skip this step. This case, the chip surface, a bit dirty, but do not affect the operation of UV effects on the chip. The final step is to find the location of the protection fuse and fuse protection under exposure to UV light. General use at least a 100 times magnification microscope, from the programming voltage input pin of the connection tracking in, to find protection fuse. If there is no microscope, the use of different parts of the chip is exposed to ultraviolet light and observe the results under the simple search mode. Operation applied opaque paper cover to protect the program memory chips are not erased by ultraviolet light. Will protect the fuse exposed under UV light 5 to 10 minutes to destroy the protection bit of the protective effect, use a simple programmer can directly read the contents of program memory. The use of the protective layer to protect the MCU EEPROM cell, using ultraviolet light reset protection circuit is not feasible. For this type of MCU, the general use of microprobe technology to read the memory contents. In the chip package is opened, the chip placed under the microscope can easily find from the memory circuit connected to other parts of the data bus. For some reason, the chip lockbit programming mode is not locked in the memory of the visit. Advantage of this flaw on the data lines to probe the above data can be read all you want. In programming mode, restart the process of reading and connect probe to the other data can be read online program and data memory, all of the information. There is also a possible means of attack is the use of microscopy and laser cutting machines and other equipment to find the fuse protection to this part of the circuit tracing and linking all the signal lines. Because of the design defects, so long as cut off from other circuit protection fuse to a one signal line, you can ban the entire protection. For some reason, this thread is very far from the other line, so the use of laser cutting machine can cut the wire without affecting the adjacent line. In this way, using a simple programmer can directly read the contents of program memory. Although the most mon single chip microcontroller has fuse blown inside the code protection features, but because of general lowend MCU is not positioning the production of safe products, so they often do not provide targeted preventive measures and the low level of security. MCU applications with a broad, large sales volume, mission processing and transfer of technology between firms frequently spilled a lot of technical data, making use of loopholes in the design of such chips and test interface manufacturer, and by modifying the invasive type fuse protection bits, etc. means of attack or invasiontype attack to read MCU39。s internal procedures have bee easier. About mon single chip STC microcontroller STC39。s mainly based on the 8051 microcontroller core is a new generation of enhanced MCU, the instruction code is fully patible with the traditional 8051, 8 to 12 times faster, with ADC, 4 Road, PWM, dual serial ports, a global unique ID, encryption of good, strong antiinterference. PIC Microcontroller: MICROCHIP39。s products is its prominent feature is a small, low power consump