ort82g5 Lattice Semiconductor Corp., ort82g5 Datasheet - Page 78

• Manufacturer Part Number: ort82g5
• Description: Xaui And Fc Fpscs
• Manufacturer: Lattice Semiconductor Corp.

Lattice Semiconductor
Input Eye-Mask Characterization
Figure 39. provides an eye-mask characterization of the SERDES receiver input. The eye-mask is specified below
for two different eye-mask heights. It provides guidance on a number of input parameters, including signal ampli-
tude and rise time limits, noise and jitter limits, and P and N input skew tolerance. Almost all detrimental character-
istics of transmit signal and the interconnection link design result in eye-closure. This, combined with the eye-
opening limitations of the line receiver, can provide a good indication of a link’s ability to transfer data error-free.
The Clock and Data Recovery (CDR) portion of the ORT42G5 and ORT82G5 SERDES receiver has the ability to
filter incoming signal jitter that is below the clock recovery PLL bandwidth (about 3 MHz). The eye-mask specifica-
tions of Table 37 are for jitter frequencies above the PLL bandwidth of the CDR, which is a worst case condition.
When jitter occurs at frequencies below the PLL bandwidth, the receiver jitter tolerance is significantly better. For
this case error-free data detection can occur even with a completely closed eye-mask.
Figure 39. Receive Data Eye-Diagram Template (Differential)
Table 37. Receiver Eye-Mask Specifications
Input Data
Eye Opening Width (H)@ 3.125Gbps
Eye Opening Width (T)@ 3.125Gbps
Eye Opening Width (H)@ 3.125Gbps
Eye Opening Width (T)@ 3.125Gbps
Eye Opening Width (H)@ 2.5Gbps
Eye Opening Width (T)@ 2.5Gbps
Eye Opening Width (H)@ 2.5Gbps
Eye Opening Width (T)@ 2.5Gbps
1. With PRBS 2^7-1 data pattern, 10 MHz sinusoidal jitter, all channels operating, FPGA logic active, REFCLK jitter
of 30 ps., T
1.2V
A
= 0
Parameter
o
C to 85
o
C, 1.425V to 1.575V supply.
V
1
78
V=175 mV diff
V=175 mV diff
V=600 mV diff
V=600 mV diff
V=175 mV diff
V=175 mV diff
V=600 mV diff
V=600 mV diff
ORCA ORT42G5 and ORT82G5 Data Sheet
UI
Conditions
H
T
1
1
1
1
1
1
1
1
Value
0.55
0.15
0.35
0.10
0.42
0.15
0.33
0.10
U
U
U
U
U
U
U
U
Unit
IP-P
IP-P
IP-P
IP-P
IP-P
IP-P
IP-P
IP-P