Spartan-6 FPGA GTP Transceiver Wizard v1.8
29
UG546 (v1.8) December 14, 2010
Generating the Core
Preemphasis, Termination, and Equalization
The Preemphasis, Termination, and Equalization screen (page 6) of the Wizard
(
) allows you to set the preemphasis, termination, and equalization options.
details the preemphasis and differential swing settings.
X-Ref Target - Figure 3-10
Figure 3-10:
Preemphasis, Termination and Equalization - Page 6
Table 3-12:
Preemphasis and Differential Swing
Option
Description
Preemphasis Level
Specifies the output pre-emphasis setting in 6.5% steps from 0% to approximately 45%. Selecting
Use TXPREEMPHASIS port
enables the optional TXPREEMPHASIS configuration port to
dynamically set the pre-emphasis level.
The PCI EXPRESS example uses the default setting of
000
(0%). See the
Spartan-6 FPGA GTP
Transceivers User Guide
for a table mapping TXPREEMPHASIS value settings to pre-emphasis
levels.
Main Driver
Differential Swing
Specifies the differential swing level for the transmitter main driver in 100 mV steps from
approximately 300 mV to 1400 mV. Can also be set to zero. Selecting
Use TXDIFFCTRL port
enables the optional TXDIFFCTRL configuration port to dynamically set the swing level.
The PCI EXPRESS example uses the default setting
1001
(1110 mV). See the
Spartan-6 FPGA GTP
Transceivers User Guide
for a table mapping TXDIFFCTRL value settings to differential swing
levels.