I/O duty cycle and skew control
    1.
    发明授权
    I/O duty cycle and skew control 有权
    I / O占空比和偏移控制

    公开(公告)号:US07525360B1

    公开(公告)日:2009-04-28

    申请号:US11735401

    申请日:2007-04-13

    IPC分类号: H03K3/017

    摘要: Circuits, methods and apparatus are provided to control the duty cycle of a signal. The rising and falling edges of a signal can be delayed independently to provide the selection or tuning of the duty cycle of the signal. Additionally, the delays can be used to reduce skew among both edges of signals being provided or transmitted by a data interface. The delays can be made to not cause a high-Z during a transition of the signal.

    摘要翻译: 提供电路,方法和装置来控制信号的占空比。 可以独立地延迟信号的上升沿和下降沿以提供信号占空比的选择或调谐。 此外,延迟可以用于减少由数据接口提供或发送的信号的两个边缘之间的偏差。 可以在信号转换期间延迟不会引起高电平。

    Self-compensating delay chain for multiple-date-rate interfaces
    3.
    发明授权
    Self-compensating delay chain for multiple-date-rate interfaces 有权
    多速率接口的自补偿延迟链

    公开(公告)号:US07200769B1

    公开(公告)日:2007-04-03

    申请号:US10037861

    申请日:2002-01-02

    IPC分类号: G06F1/04

    摘要: Methods and apparatus for delaying a clock signal for a multiple-data-rate interface. An apparatus provides an integrated circuit including a frequency divider configured to receive a first clock signal and a first variable-delay block configured to receive an output from the frequency divider. Also included is a phase detector configured to receive the first clock signal and an output from the first variable-delay block, and an up/down counter configured to receive an output from the phase detector. A second variable-delay block is configured to receive a second clock signal and a plurality of flip-flops are configured to receive an output from the second variable-delay block. The first variable-delay block and the second variable-delay block are configured to receive an output from the up/down counter.

    摘要翻译: 用于延迟多数据速率接口的时钟信号的方法和装置。 一种装置提供一种集成电路,其包括配置成接收第一时钟信号的分频器和被配置为接收来自分频器的输出的第一可变延迟块。 还包括相位检测器,被配置为接收第一时钟信号和来自第一可变延迟块的输出,以及配置为接收来自相位检测器的输出的上/下计数器。 第二可变延迟块被配置为接收第二时钟信号,并且多个触发器被配置为从第二可变延迟块接收输出。 第一可变延迟块和第二可变延迟块被配置为从加/减计数器接收输出。

    On/off reference voltage switch for multiple I/O standards
    5.
    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
    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: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。

    Systems and methods for on-chip impedance termination
    8.
    发明授权
    Systems and methods for on-chip impedance termination 有权
    用于片上阻抗终止的系统和方法

    公开(公告)号:US06603329B1

    公开(公告)日:2003-08-05

    申请号:US10044459

    申请日:2002-01-11

    IPC分类号: H03K1716

    CPC分类号: H04L25/0278 H04L25/0298

    摘要: Techniques for on-chip impedance termination are provided that substantially reduce the number of external resistors that are need to provide impedance termination at a plurality of pairs of differential input/output (I/O) pins. On-chip impedance termination circuits of the present invention may include an amplifier, a feedback loop, and an impedance termination circuit. A reference voltage is provided to a first input terminal of the amplifier. A feedback loop is coupled between an output terminal of the amplifier and a second input terminal of the amplifier. The amplifier drives its output voltage so that the voltage at the second input terminal matches the voltage at the first input terminal. The output voltage of the amplifier determines the resistance of the impedance termination circuit. The impedance termination circuit is coupled between differential I/O pins.

    摘要翻译: 提供用于片上阻抗终止的技术,其大大减少了需要在多对差分输入/输出(I / O)引脚上提供阻抗终端的外部电阻器的数量。 本发明的片上阻抗终端电路可以包括放大器,反馈回路和阻抗终端电路。 将参考电压提供给放大器的第一输入端。 反馈回路耦合在放大器的输出端和放大器的第二输入端之间。 放大器驱动其输出电压,使得第二输入端子处的电压与第一输入端子处的电压匹配。 放大器的输出电压决定了阻抗终端电路的电阻。 阻抗端接电路耦合在差分I / O引脚之间。

    Circuit for providing clock signals with low skew
    9.
    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。