On/off reference voltage switch for multiple I/O standards
    3.
    发明授权
    On/off reference voltage switch for multiple I/O standards 有权
    用于多个I / O标准的开/关参考电压开关

    公开(公告)号:US06911860B1

    公开(公告)日:2005-06-28

    申请号:US10037716

    申请日:2001-11-09

    IPC分类号: H03K17/35

    摘要: A switch circuit selectively provides a reference voltage, needed in some I/O standards, to a logic device. The circuit receives a dedicated power supply that is different from the device's I/O supply. It may also include a level shifting circuit for converting a master control signal having a logic level determined by a first supply to a first control signal having a logic level determined by the dedicated supply. The switch circuit also includes a transmission switch that passes the reference voltage to an output in response to at least the first control signal. The transmission switch may be a CMOS transmission gate with at least one NMOS transistor controlled by the first control signal in parallel with at least one PMOS transistor controlled by a second control signal, complementary to the first. The second control signal may be generated by another level shifting circuit and have a logic level determined by the I/O supply.

    摘要翻译: 开关电路选择性地将某些I / O标准所需的参考电压提供给逻辑器件。 该电路接收与设备的I / O电源不同的专用电源。 其还可以包括电平移位电路,用于将具有由第一电源确定的逻辑电平的主控制信号转换成具有由专用电源确定的逻辑电平的第一控制信号。 开关电路还包括传输开关,其响应于至少第一控制信号将参考电压传递到输出。 传输开关可以是CMOS传输门,其中至少一个NMOS晶体管由第一控制信号控制,与由与第一控制信号互补的第二控制信号控制的至少一个PMOS晶体管并联。 第二控制信号可以由另一电平移位电路产生并具有由I / O电源确定的逻辑电平。

    Circuit for providing clock signals with low skew
    4.
    发明授权
    Circuit for providing clock signals with low skew 有权
    提供低偏移时钟信号的电路

    公开(公告)号:US06731142B1

    公开(公告)日:2004-05-04

    申请号:US10412705

    申请日:2003-04-10

    IPC分类号: H03K2100

    CPC分类号: H03M9/00 G06F1/08 H03K5/135

    摘要: A digital, preferably programmable, circuit is disclosed for providing one or more clock signals with variable frequency and/or phase. The clock signals exhibit a low amount of skew relative to other clock signals and data signals provided by the circuit. In one embodiment, the circuit includes a plurality of channels each having a parallel-in/serial-out shift register, a flip-flop, and a delay circuit. The shift register can receive data bits in data channels or clock frequency select bits in frequency-divided clock channels. The serial output from the register acts as an input for the flip flop, both of which are triggered by an input reference clock. The delay circuit delays the input reference clock. In each channel, a multiplexer is configured to select the clock or data channel output from the register, flip-flop, and delay circuit outputs. Since the delays in all output paths are matched, skew is minimized.

    摘要翻译: 公开了一种数字,优选可编程的电路,用于提供具有可变频率和/或相位的一个或多个时钟信号。 时钟信号相对于由该电路提供的其它时钟信号和数据信号呈现低的偏移量。 在一个实施例中,电路包括多个通道,每个通道具有并行/串行输出移位寄存器,触发器和延迟电路。 移位寄存器可以在分频时钟通道中的数据通道或时钟频率选择位中接收数据位。 来自寄存器的串行输出用作触发器的输入,两者均由输入参考时钟触发。 延迟电路延迟输入参考时钟。 在每个通道中,多路复用器被配置为选择从寄存器,触发器和延迟电路输出输出的时钟或数据通道。 由于所有输出路径中的延迟相匹配,所以偏斜最小化。

    Circuit for providing clock signals with low skew
    6.
    发明授权
    Circuit for providing clock signals with low skew 有权
    提供低偏移时钟信号的电路

    公开(公告)号:US06549045B1

    公开(公告)日:2003-04-15

    申请号:US10043620

    申请日:2002-01-11

    IPC分类号: H03K2100

    CPC分类号: H03M9/00 G06F1/08 H03K5/135

    摘要: A digital, preferably programmable, circuit is disclosed for providing one or more clock signals with variable frequency and/or phase. The clock signals exhibit a low amount of skew relative to other clock signals and data signals provided by the circuit. In one embodiment, the circuit includes a plurality of channels each having a parallel-in/serial-out shift register, a flip-flop, and a delay circuit. The shift register can receive data bits in data channels or clock frequency select bits in frequency-divided clock channels. The serial output from the register acts as an input for the flip flop, both of which are triggered by an input reference clock. The delay circuit delays the input reference clock. In each channel, a multiplexer is configured to select the clock or data channel output from the register, flip-flop, and delay circuit outputs. Since the delays in all output paths are matched, skew is minimized.

    摘要翻译: 公开了一种数字,优选可编程的电路,用于提供具有可变频率和/或相位的一个或多个时钟信号。 时钟信号相对于由该电路提供的其它时钟信号和数据信号呈现低的偏移量。 在一个实施例中,电路包括多个通道,每个通道具有并行/串行输出移位寄存器,触发器和延迟电路。 移位寄存器可以在分频时钟通道中的数据通道或时钟频率选择位中接收数据位。 来自寄存器的串行输出用作触发器的输入,两者均由输入参考时钟触发。 延迟电路延迟输入参考时钟。 在每个通道中,多路复用器被配置为选择从寄存器,触发器和延迟电路输出输出的时钟或数据通道。 由于所有输出路径中的延迟相匹配,所以偏斜最小化。

    Programmable I/O element circuit for high speed logic devices
    9.
    发明授权
    Programmable I/O element circuit for high speed logic devices 失效
    用于高速逻辑器件的可编程I / O元件电路

    公开(公告)号:US06853215B1

    公开(公告)日:2005-02-08

    申请号:US10685355

    申请日:2003-10-09

    摘要: A programmable I/O element for an I/O terminal of a logic array is suitable for operating according to high speed 110 modes such as double data rate and zero bus turnaround. The I/O element may include an input block with two registers for registering input signals from the terminal upon alternate clock edges. In addition or alternatively, it may include an output block with two registers that separately register output signals from the array on the same clock edge and a multiplexer that alternately outputs those signals. For bidirectional terminals, the multiplexer output is connectable to the I/O terminal via an output buffer, and an output enable block provides an enable signal to a gating input of the output buffer. Programmable delays may be included in the input, output, and output enable paths, in particular to provide a slower turn-on time than turn-off time for the output buffer.

    摘要翻译: 用于逻辑阵列的I / O端子的可编程I / O元件适用于根据高速110模式(例如双数据速率和零总线周转)进行操作。 I / O元件可以包括具有两个寄存器的输入块,用于在备用时钟边缘上从终端注册输入信号。 另外或替代地,它可以包括具有两个寄存器的输出块,该两个寄存器在相同的时钟沿上单独地寄存来自阵列的输出信号,以及交替地输出这些信号的多路复用器。 对于双向端子,多路复用器输出可通过输出缓冲器连接到I / O端子,并且输出使能块向输出缓冲器的选通输入提供使能信号。 可编程延迟可以包括在输入,输出和输出使能路径中,特别是提供比输出缓冲器的关断时间更慢的导通时间。