Example R21 Delay Calculation - 8.12 English - PG056

CPRI LogiCORE IP Product Guide (PG056)

Document ID
PG056
Release Date
2024-12-13
Version
8.12 English

An example of the delay calculation follows, given that:

  • Line Rate = 1,228.8 Mb/s
  • UI = 813.8 ps
  • Transceiver Latency = 150 UI
  • Datapath Latency = 100 UI
  • Slave CDC FIFO = 160 UI
  • Slave Barrel Shift = 16 UI
  • Slave Coarse Timer = 340 UI
  • Master CDC FIFO = 1,340 UI
  • Master Barrel Shift = 13 UI
  • Master Coarse Timer = 15,000 UI

Cable Delay = (15000 - (150 + 13 + 100 + 1340) - (340 + 150 + 16 + 100 + 160))/2

Cable Delay = 6,315.5 UI = 5,139.55 ns

Table 1. Line Speed To UI Conversion Factors
Line Speed (Mb/s) 1 UI (ps)
614.4 1,627.6
1,228.8 813.8
2,457.6 406.9
3,072.0 325.5
4,915.2 203.45
6,144.0 162.76
8,110.08 123.303
9,830.4 101.725
10,137.6 98.643
12,165.12 82.202
24,330.24 41.101