1. MAX® 10 I/O Overview
2. MAX® 10 I/O Architecture and Features
3. MAX® 10 I/O Design Considerations
4. MAX® 10 I/O Implementation Guides
5. GPIO Lite Intel® FPGA IP References
6. MAX® 10 General Purpose I/O User Guide Archives
7. Document Revision History for the MAX® 10 General Purpose I/O User Guide
2.3.2.1. Programmable Open Drain
2.3.2.2. Programmable Bus Hold
2.3.2.3. Programmable Pull-Up Resistor
2.3.2.4. Programmable Current Strength
2.3.2.5. Programmable Output Slew Rate Control
2.3.2.6. Programmable IOE Delay
2.3.2.7. PCI Clamp Diode
2.3.2.8. Programmable Pre-Emphasis
2.3.2.9. Programmable Differential Output Voltage
2.3.2.10. Programmable Emulated Differential Output
2.3.2.11. Programmable Dynamic Power Down
3.1. Guidelines: VCCIO Range Considerations
3.2. Guidelines: Voltage-Referenced I/O Standards Restriction
3.3. Guidelines: Enable Clamp Diode for LVTTL/LVCMOS Input Buffers
3.4. Guidelines: Adhere to the LVDS I/O Restrictions Rules
3.5. Guidelines: I/O Restriction Rules
3.6. Guidelines: Placement Restrictions for 1.0 V I/O Pin
3.7. Guidelines: Analog-to-Digital Converter I/O Restriction
3.8. Guidelines: External Memory Interface I/O Restrictions
3.9. Guidelines: Dual-Purpose Configuration Pin
3.10. Guidelines: Clock and Data Input Signal for MAX® 10 E144 Package
3.11. Guidelines: MultiVolt Input for I/O Banks with 3.3 V, 3.0 V, 1.8 V, or 1.5 V VCCIO
3.12. Guidelines: LVTTL/LVCMOS I/O Utilization for MAX® 10 FPGA Package B610
2.3.2.8. Programmable Pre-Emphasis
The differential output voltage (VOD) setting and the output impedance of the driver set the output current limit of a high-speed transmission signal. At a high frequency, the slew rate may not be fast enough to reach the full VOD level before the next edge, producing pattern-dependent jitter. Pre-emphasis momentarily boosts the output current during switching to increase the output slew rate.
Pre-emphasis increases the amplitude of the high-frequency component of the output signal. This increase compensates for the frequency-dependent attenuation along the transmission line.
The overshoot introduced by the extra current occurs only during change of state switching. This overshoot increases the output slew rate but does not ring, unlike the overshoot caused by signal reflection. The amount of pre-emphasis required depends on the attenuation of the high-frequency component along the transmission line.
Figure 7. LVDS Output with Programmable Pre-Emphasis
Field | Assignment |
---|---|
To | tx_out |
Assignment name | Programmable Pre-emphasis |
Allowed values | 0 (disabled), 1 (enabled). Default is 1. |