Assist Signal Interface Ports - 1.0 English

PCI Express PHY LogiCORE IP Product Guide (PG239)
Document ID
PG239
Release Date
2022-06-03
Version
1.0 English

Assist signals are used to support the functionality of PCIe PHY IP according to the MAC LTSSM states.

Table 1. Assist Signal
Name Width Direction Clock Domain Description
as_mac_in_detect 1 Input pclk Tell the PHY to switch the Receiver Termination between VTT and GND. Set to 1 when MAC is in:
  • Detect.Quiet
  • Detect.Active

Set to 0 when in other states.
as_cdr_hold_req 1 Input pclk Tell the PHY when to hold CDR. Set to 1 when MAC is in:
  • Recovery.Speed
  • L1.Entry
  • L1.Idle
  • Loopback.Speed
  • Loopback.Entry

Set to 0 when in other states.
  1. The LTSSM states and substates mentioned in the description above are indicative. Your configured MAC implementation might not have the same substates as indicated. Generate the above mentioned assist signals as per states implemented in your configured MAC.