公开(公告)号：US07181767B1

公开(公告)日：2007-02-20

申请号：US09851757

申请日：2001-05-08

申请人： Rajeev Sethia ,  Franklyn H. Story ,  Mark Buer

发明人： Rajeev Sethia ,  Franklyn H. Story ,  Mark Buer

IPC分类号： H04L9/00

CPC分类号： G06F21/75 ,  G06F21/83

摘要： The present invention increases the difficulty of interpreting electromagnetic emissions from a keypad system by facilitating randomness in the electromagnetic emissions associated with a particular key activation. A keypad security circuit utilizes a set of digital values that varies over both time and the bits as a keypad driver word applied to a keypad attribute (e.g., a row or column). The keypad security system of the present invention drives the varying strong keypad driver signal to an attribute of a keypad switch matrix (e.g., the rows or columns), applies an independently configured weak driver signals to the opposing attribute of the keypad switch matrix, retrieves a resulting signal from the opposing attribute, and interprets the results to determine if a switch included in a keypad system was activated (e.g., a key is pressed).

摘要翻译： 本发明通过促进与特定密钥激活相关联的电磁辐射中的随机性增加了解释来自键盘系统的电磁辐射的难度。 小键盘安全电路利用一组数字值，这两组数字值随时间而改变，并将位作为应用于小键盘属性（例如，行或列）的小键盘驱动程序字。 本发明的键盘安全系统将变化的强键盘驱动器信号驱动到键盘开关矩阵（例如，行或列）的属性，将独立配置的弱驱动器信号应用于键盘开关矩阵的相对属性，检索 来自相对属性的结果信号，并解释结果以确定包括在键盘系统中的开关是否被激活（例如，按下一个键）。

公开(公告)号：US06694441B1

公开(公告)日：2004-02-17

申请号：US09713073

申请日：2000-11-15

申请人： Rajeev Sethia

发明人： Rajeev Sethia

IPC分类号： G06F132

CPC分类号： G06F1/324 ,  G06F1/3203 ,  G06F1/3287 ,  Y02D10/126 ,  Y02D10/171

摘要： A power management system permits power-reduced operation of selected circuit blocks in a manner that requires no modification to other bus-coupled circuit blocks attempting to communicate with such selected circuit blocks. Consistent with one embodiment of the present invention, the approach is implemented in a digital electronic circuit arrangement having an accessing circuit block coupled to a clocked circuit block over a data bus. The clocked circuit block is power managed by decreasing, e.g., reducing or blocking, the clock speed to the clocked circuit block which impedes its ability communicate over the data bus. Once the clocked circuit block is set in a reduced power mode, the bus is monitored for data-access communications from the accessing circuit block to the clocked circuit block. In response to such a communication, a substitute response is generated on the data bus, directed to the accessing circuit block, and the clock speed to the clocked circuit block, is increased and brought out of the reduced power mode for further communications with the accessing circuit block.

摘要翻译： 电源管理系统允许以不需要修改尝试与这些所选择的电路块进行通信的其它总线耦合电路块的方式来对所选择的电路块进行功率降低的操作。 与本发明的一个实施例一致，该方法在具有通过数据总线耦合到计时电路块的访问电路块的数字电子电路装置中实现。 时钟控制的电路块通过减少（例如，减少或阻塞）阻塞其能力通过数据总线通信的时钟电路块的时钟速度来进行功率管理。 一旦将时钟电路块设置为降低功率模式，则监视总线以从访问电路块到时钟电路块的数据访问通信。 响应于这样的通信，在数据总线上产生针对访问电路块的代替响应，并且向时钟电路块的时钟速度增加并且从降低的功率模式中脱离，以进一步与访问 电路块。