We provide enhanced high-performance PCI Express clock and timing solutions. Each design is fully tested and validated for a variety of industry needs.
在接收端数据和时钟之间的传输延迟增量(时钟偏斜(Clock Skew))必须要小于等于12ns。通常允许PCIE卡上的时钟线长不大于4inch。特别注意这点,涉及到我们实际PCB走线。这无疑对大型电路板上或跨板的 PCIe 设备间布局布线形成巨大挑战。 采用Common Clock 支持时钟扩频(SSC, Spread Spectrum Clock) 且对参考时钟的要求...
PCIe时钟偏差补偿 (Clock Tolerance Compliance) PCIe 时钟偏差出现的原因 为了减少EMI电磁辐射,芯片厂家往往会对时钟进行扩频(Spread Spectrum Clocking,SSC)。即便不进行SSC,受限于PLL工艺,时钟频率也很难做到与期望频率完全一致。这样一来,PCIe发送端与接收端存在时钟偏差,尤其是频率偏差。当收发端时钟存在偏差时,如果...
简介:PCIe时钟偏差补偿 (Clock Tolerance Compliance) 1. PCIe 时钟偏差 1.1 PCIe 时钟偏差出现的原因 为了减少EMI电磁辐射,芯片厂家往往会对时钟进行扩频(Spread Spectrum Clocking,SSC)。即便不进行SSC,受限于PLL工艺,时钟频率也很难做到与期望频率完全一致。 这样一来,PCIe发送端与接收端存在时钟偏差,尤其是频率偏差。
The Port Reference Clock inputs support Spread spectrum clocking (SSC) for reduced EMI and allow isolation of this SSC from the rest of the Switch. The PCI Express Base 2.0 specification permits SSC down-spread technique which only allows from +0% to -0.5% (+0 to -5000 ppm) of the ...
Spread spectrum clocking (SSC) isolation,开展频 Common mode with and without SSC,同源时钟模式 Separate reference clock independent SSC (SRIS),独立时钟,开展频 Separate reference clock with no SSC (SRNS),独立时钟,不开展频 SSC isolation supporting up to eight external PCIe input reference clocks (S...
This application note outlines how to configure the SSCTrack math operator settings to perform spread spectrum clock demodulation of serial data waveforms. Read App Note PCI Express 6.0 Electrical Compliance Test Overview PCIe® 6.0 FYI compliance and interoperability testing is expected to begin so...
ClKS:ClKS是“Clock Requester”(时钟请求器)的缩写,是一种用于PCIe电源管理的功能。ClKS是一个信号线,用于向PCIe设备发送时钟请求。PCIe设备可以通过控制ClKS信号来控制其电源管理状态,包括进入睡眠模式以节省功耗。 MSI-X是一种扩展的中断传输机制,它是MSI(Message Signaled Interrupt)的一种扩展,用于在多处理器系...
Common Clock Architecture (CC),通用参考时钟架构,收发端共享同一个参考时钟。三种 PCIe 参考时钟架构中,Common Clock 是最为常用的一种时钟架构,采用 Common Clock 支持时钟扩频(SSC, Spread Spectrum Clock) 且对参考时钟的要求不如 Separate Clock 方案严苛。Common Clock 对于频率稳定性的要求是 ±300 ppm。
So, is really possible enable SpreadSpectrum over PCIe ref clock? Maybe that PCIe_phy shuld be configurate before some reset are cleared, or somethink like that. For sure in i.MX6DL, do that before ref_clk enable cause reset. In my case is importat spread ref_clk because 100Mhz creat...