Calibration of Rx Stress Test Signals for PCIe 3.0
应用文章
This paper describes the calibration of the receiver-stress signal according to the base specification of PCIe 3.0. This differs in the following ways from what was common practice at lower data rates, e.g., for PCI Express rev. 2.0:
- The specifications relate to a point inside the RX, which makes post processing of the measured RX test signal necessary
- Accurate measurement of this test signal is impractical and error prone due to the noise floor of current real time oscilloscopes (RTOs); therefore,
- Calibration of deliberately injected impairments is separated from the characterization of the test setup, and
- The RX test signal with the intended eye opening is constructed using simulation software
- Other aspects of the PCIe3 RX test related to the CEM specification, such as the link training procedure, are not included in this document as the related test procedures are not yet defined (see Figure 1)