DK-DEV-4SGX230N Altera, DK-DEV-4SGX230N Datasheet - Page 293

• Manufacturer Part Number: DK-DEV-4SGX230N
• Description: KIT DEVELOPMENT STRATIX IV
• Manufacturer: Altera
• Series: Stratix® IVr
• Type: FPGAr

Specifications of DK-DEV-4SGX230N

• Contents: Development Board, Universal Power Supply, Cables and Software
• Silicon Manufacturer: Altera
• Core Architecture: FPGA
• Core Sub-architecture: Stratix
• Silicon Core Number: EP4S
• Silicon Family Name: Stratix IV GX
• Rohs Compliant: Yes
• For Use With/related Products: EP4SGX230K
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Other names: 544-2594

Chapter 8: High-Speed Differential I/O Interfaces and DPA in Stratix IV Devices
Differential Transmitter
Figure 8–10. Quartus II Software Assignment Editor—Programmable V
February 2011 Altera Corporation
Pre-emphasis is an important feature for high-speed transmission. Without
pre-emphasis, the output current is limited by the V
impedance of the driver. At high frequency, the slew rate may not be fast enough to
reach full V
With pre-emphasis, the output current is boosted momentarily during switching to
increase the output slew rate. The overshoot introduced by the extra current happens
only during switching and does not ring, unlike the overshoot caused by signal
reflection. The amount of pre-emphasis needed depends on the attenuation of the
high-frequency component along the transmission line. The Quartus II software
allows four settings for programmable pre-emphasis—zero (0), low (1), medium (2),
and high (3). The default setting is low.
The V
high (2), and high (3). The default setting is medium low.
Programmable V
You can statically assign the V
the assignment name for programmable V
software Assignment Editor.
Table 8–8. Quartus II Software Assignment Editor
Figure 8–10
from the Quartus II software Assignment Editor.
To
Assignment name
Allowed values
OD
is also programmable with four settings: low (0), medium low (1), medium
OD
shows the assignment of programmable V
before the next edge, producing pattern-dependent jitter.
OD
tx_out
Programmable Differential Output Voltage (V
0, 1, 2, 3
OD
settings from the Assignment Editor.
OD
OD
and its possible values in the Quartus II
OD
OD
setting and the output
for a transmit data output
Stratix IV Device Handbook Volume 1
OD
)
Table 8–8
lists
8–15