公开(公告)号：US20040073807A1

公开(公告)日：2004-04-15

申请号：US10268871

申请日：2002-10-10

Applicant: STMicroelectronics, Inc.

Inventor： Tom Youssef

IPC: G06F012/14

CPC classification number: G01R21/133 ,  G01R22/066

Abstract: An electronic timer may include a clock reference signal generator and a real time clock (RTC) circuit for generating real time data based upon the clock reference signal. The RTC circuit may include a plurality of registers each for storing a respective bit of the real time data. Further, each register may include a master latch for initially storing the real time data bit, a slave latch for subsequently storing the real time data bit, and a user latch for storing the real time data bit from the slave latch. The RTC circuit may further include a controller for causing at least some of the registers to increment based upon the clock reference signal. Additionally, the electronic timer may also advantageously include a tamper circuit for receiving a tamper event signal and causing each of the user latches to hold a time stamp therein.

Abstract translation: 电子计时器可以包括时钟参考信号发生器和用于基于时钟参考信号产生实时数据的实时时钟（RTC）电路。 RTC电路可以包括多个寄存器，每个寄存器用于存储实时数据的相应位。 此外，每个寄存器可以包括用于初始存储实时数据位的主锁存器，用于随后存储实时数据位的从锁存器和用于从从锁存器存储实时数据位的用户锁存器。 RTC电路还可以包括用于使得至少一些寄存器基于时钟参考信号而增加的控制器。 此外，电子计时器还可以有利地包括用于接收篡改事件信号的篡改电路，并使每个用户锁存器在其中保持时间戳。

公开(公告)号：US20040189481A1

公开(公告)日：2004-09-30

申请号：US10404885

申请日：2003-03-31

Applicant: STMicroelectronics, Inc.

Inventor： Tom Youssef

IPC: G08B021/00

CPC classification number: H03K17/18 ,  G01R31/31721 ,  G08B13/02 ,  H01H9/167

Abstract: A circuit for detecting the state of a switch having a first circuit which substantially periodically attempts to provide a voltage across the switch. A second circuit detects the state of the switch by monitoring the voltage across the switch, and responsively generates an output having a voltage level representative of the voltage appearing across the switch.

Abstract translation: 用于检测具有第一电路的开关的状态的电路，其基本上周期性地尝试在开关上提供电压。 第二电路通过监视开关两端的电压来检测开关的状态，并且响应地产生具有代表开关两端出现的电压的电压电平的输出。

公开(公告)号：US20040160330A1

公开(公告)日：2004-08-19

申请号：US10754023

申请日：2004-01-08

Applicant: STMicroelectronics, Inc.

Inventor： David C. McClure ,  Tom Youssef

IPC: G08B021/00

CPC classification number: G11C5/141 ,  Y10T307/615 ,  Y10T307/625 ,  Y10T307/826

Abstract: An integrated circuit and method for providing a switchover from the primary power source to the secondary power source to prevent a volatile element from losing stored data. The integrated circuit includes a forced power source switchover circuit for detecting that the supply level of the primary power source drops below a predefined threshold level. A switchover circuit on the integrated circuit initiates a switchover operation based upon the forced power source switchover circuit detecting that the supply level being received from the primary power source drops below the predefined threshold level. The detection by the forced power source switchover circuitry may occur on a signal level that transitions faster than a predetermined negative rate of change. The integrated circuit may be incorporated in any system having volatile elements, such as memory or a clock.