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[通信技术]smart card 3 |
gun 发表于 2005/1/14 17:26:34 |
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The ICC itself
The ICC cards usually employ a low power micro-controller like Intel® 8051 or AVRs from ATMEL® as the core CPU with the clock frequency up to 5 MHz or so. These micro-controllers are available in 8, 16 or 32 bit flavors. Basically the decision is governed by the requirements of the applications the card needs to support.
The architecture of these CPUs varies as I mentioned above. The Intel uses the Von Neumann architecture where as the AVRs from ATMEL use the Harvard architecture.
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Figure 3: The Harvard Architecture (Source: http://www.ee.nmt.edu/~rison/ee308_spr99/supp/990119/harvard.gif)
Also some ICCs also use two CPUs just to enhance their capabilities. For providing advanced security features such as using RSA for cryptography much more processing power is required so this is provided the help of these special purpose co-processors. The ICCs with these chips are expensive as compared to single chip ICCs. | |
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