I/O standards Definition
Standards that uniquely define the input and output (VCCIO) voltage, reference VREF voltage (if applicable), and the types of input and output buffers used for I/O pins.
The following table lists the I/O standards that are available, and the device families that support them. The table also lists the Intel® Quartus® Prime Settings File (.qsf) settings keyword for each I/O standard.
| I/O Standard | Device Family Support | QSF Keyword | 
|---|---|---|
| 1.2-V | supported device (Stratix® V , Intel® MAX® 10, MAX® V,Arria® V series, and Cyclone® V series) families | "1.2 V", "1.2V", "1.2-V" | 
| 1.2-V HSTL Class I and II | supported device (Intel® MAX® 10, Arria® series, Cyclone® IV , Cyclone® V , Stratix® IV, and Stratix® V ) families | "1.2- V HSTL", "1.2- V HSTL Class I", "1.2- V HSTL Class II" | 
| 1.2-V HSUL | supported device (Intel® MAX® 10, Intel® Arria® 10 ,Arria® V , Cyclone® V , and Stratix® V ) families | "1.2-V HSUL" | 
| 1.2-VPCML | supported device (Arria® series, Cyclone® IV GX, Stratix® IV, and Stratix® V ) families | "1.2- V PCML" | 
| 1.4-V PCML | supported device (Stratix®IV, and Stratix®V) families | "1.4-V PCML" | 
| 1.5-V | All Intel devices | "1.5 V", "1.5V", "1.5- V" | 
| 1.5-VHSTL Class I | supported device (Intel® MAX® 10, Arria® series, Cyclone® IV , and Stratix® series) families | "1.5- V HSTL Class I", "HSTL Class I" | 
| 1.5-VHSTL Class II | supported device (Arria® series, Cyclone® IV , and Stratix® series) families | "1.5- V HSTL Class II", "HSTL Class II" | 
| 1.5-VPCML | supported device (Cyclone® IV GX, Stratix® IV, and Stratix® V ) families | "1.5- V PCML" | 
| 1.8V | All Intel devices | "1.8 V", "1.8V", "1.8- V" | 
| 1.8-V HSTL Class I and II | supported device (Intel® MAX® 10, Arria® series, Cyclone® IV , and Stratix® series) families | "1.8- V HSTL Class I", "1.8- V HSTL Class II" | 
| 2.5-V | All Intel device families supported by the Intel® Quartus® Prime software | "2.5 V", "2.5V", "2.5- V" | 
| 2.5 V LVDS | Arria® V series | LVDS | 
| 2.5-V PCML | supported device (Cyclone® IV GX, Stratix® IV, and Stratix® V ) families | "2.5-V PCML" | 
| 2.5-V Schmitt Trigger Input | MAX® V devices | "2.5V Schmitt Trigger Input" | 
| 3.0-V LVCMOS | supported device (Arria® V, Cyclone® IV , MAX® V, and Cyclone® V ) families | "3.0-V LVCMOS", "3.0V LVCMOS" | 
| 3.0-V LVTTL | supported device (Arria® V, Cyclone® IV , Cyclone® V , MAX® V) families | "3.0-V LVTTL", "3.0V LVTTL" | 
| 3.0-VPCI | supported device (Arria® V, and Stratix® IV) families | "3.0- V PCI" | 
| 3.0-VPCI-X | supported device (Arria® V, and Stratix® IV) families | "3.0- V PCI- X", "3.0- V PCI X" | 
| 3.3-V LVCMOS | All Intel device families supported by the Intel® Quartus® Prime software | "3.3-V LVCMOS", "3.3V LVCMOS", "LVCMOS" | 
| 3.3-V LVTTL | All Intel device families supported by the Intel® Quartus® Prime software | "LVTTL" | 
| 3.3-VPCI | supported device (Arria® V series, MAX® V) families | "3.3- V PCI" | 
| 3.3-VPCI-X | supported device (Arria® V) families | "3.3- V PCI- X", "3.3- V PCI X" | 
| 3.3-VPCML | supported device (Cyclone® IV GX) families | "3.3- V PCML", "PCML", " CML" | 
| 3.3-V Schmitt Trigger Input | MAX® V devices | "3.3V Schmitt Trigger Input" | 
| Bus LVDS | supported device (Cyclone® IV devices) | "Bus LVDS" | 
| Differential I/O standards | ||
| 2.5 V LVDS | supported device (Arria® V and Cylone V) families | LVDS | 
| Differential 1.2-V HSTL Class I and II | supported device (Arria® series, Cyclone®IV, Stratix®IV, and Stratix®V) families | "Differential 1.2- V HSTL", "Differential 1.2- V HSTL Class I", "Differential 1.2- V HSTL Class II" | 
| Differential 1.2-V HSUL | supported device (Arria® V, Cyclone® V , and Stratix® V ) families | "Differential 1.2-V HSUL" | 
| Differential 1.2-V SSTL | Stratix®V devices | "Differential 1.2-V SSTL" | 
| Differential 1.25-V SSTL | supported device (Arria® V, Cyclone® V , and Stratix® V series) families | "Differential 1.25-V SSTL" | 
| Differential 1.35-V SSTL | supported device (Arria® V, Cyclone® V , Stratix® V series) families | "Differential 1.35-V SSTL" | 
| Differential 1.5-V HSTL Class I | supported device (Arria®series, Cyclone®IV, and Stratix® series) families | "Differential HSTL", "Differential 1.5- V HSTL", "Differential 1.5- V HSTL Class I" | 
| Differential 1.5-V HSTL Class II | supported device (Arria® series, Cyclone® IV , Cyclone® V series, Stratix® IV, and Stratix® V ) families | "Differential HSTL Class II", "Differential 1.5- V HSTL Class II" | 
| Differential 1.5-V SSTL | supported device (Cyclone® V series and Stratix® V ) families | "Differential 1.5-V SSTL" | 
| Differential 1.5-V SSTL ClassIand II | Stratix®V devices | "Differential 1.5-V SSTL Class I", "Differential 1.5-V SSTL Class II" | 
| Differential 1.8-V HSTL ClassIand II | supported device (Arria® series, Cyclone® IV , Cyclone® V , and Stratix® series) families | "Differential 1.8- V HSTL Class I", "Differential 1.8- V HSTL Class II" | 
| Differential 1.8-V SSTL ClassIand II | supported device (Arria® series, Cyclone® IV , Cyclone® V , and Stratix® IV) families | "Differential 1.8- V SSTL Class I", "Differential 1.8- V SSTL Class II" | 
| Differential 2.5-V SSTL ClassIand II | supported device (Arria® V and Stratix® V ) families | "Differential 2.5- V SSTL Class I" "Differential 2.5- V SSTL Class II" | 
| Differential LVPECL | supported device (Arria® series, Cyclone® IV , and Stratix® series) families | "Differential LVPECL" | 
| Differential SSTL-2 ClassI | supported device (Arria® series, Cyclone® series, and Stratix® IV) families | "Differential SSTL- 2" | 
| Differential SSTL-2 ClassII | supported device (Arria® series, Cyclone® IV , and Stratix® IV) families | "Differential SSTL- 2 Class II" | 
| HCSL | supported device (Arria® series, Cyclone® IV GX, Stratix® IV, and Stratix® V ) families | "HCSL" | 
| LVDS | supported device (Arria® series, Cyclone® series, and Stratix® series) families | "LVDS" | 
| LVDS_E_1R | supported device (Stratix® IV) families | "LVDS_E_1R" | 
| LVDS_E_3R | supported device (Cyclone® IV , MAX® V, Stratix® IV, and Stratix® V ) families | "LVDS_E_3R" | 
| LVPECL | supported device (Arria® V and Cyclone® V ) families | LVEPCL | 
| mini-LVDS | supported device (Arria® V, Cyclone® IV , Stratix® IV, and Stratix® V ) families | "mini-LVDS" | 
| mini-LVDS _E_R | supported device (Stratix® IV) families | "mini-LVDS", | 
| mini-LVDS _E_3R | supported device (Cyclone® IV , Stratix® IV, and Stratix® V ) families | "mini-LVDS", | 
| RSDS | supported device (Arria® V series, Cyclone® series, Stratix® IV,and Stratix® V ) families | "RSDS" | 
| RSDS_E_1R | supported device (Cyclone® IV , and Stratix® IV) families | "RSDS_E_1R" | 
| RSDS_E_3R | supported device (Cyclone® IV , Stratix® IV, and Stratix® V ) families | "RSDS_E_3R" | 
| Schmitt Trigger Input | MAX® II devices | "2.5V Schmitt Trigger Input", "3.3V Schmitt Trigger Input" | 
| SSTL-12 | Stratix® V devices | "SSTL-12" | 
| SSTL-125 Class I | Stratix® V devices | "SSTL-125" | 
| SSTL-135 Class I | Stratix® V devices | "SSTL-135" | 
| SSTL-15 | Stratix® V deviecs | "SSTL-15" | 
| SSTL-15 Class I | supported device (Stratix® IV, and Stratix® V ) families | "SSTL- 15 Class I" | 
| SSTL-15 Class II | supported device (Stratix® IV, and Stratix® V ) families | "SSTL- 15 Class II" | 
| SSTL-18 Class I and II | supported device (Arria® series, Cyclone® IV , and Stratix® series) families | "SSTL- 18 Class I", "SSTL- 18 Class II" | 
| SSTL-2 Class I and II | supported device (Arria® series, Cyclone® series, and Stratix® series) families | "SSTL- 2 Class I", "SSTL- 2 Class II" | 
| POD12 | Intel® Arria® 10 devices | "1.2-V POD | 
| Differential POD12 | Intel® Arria® 10 devices | "Differential 1.2-V POD | 
| High Speed Differential | Intel® Arria® 10 devices | "High Speed Differential I/O" | 
| PPDS | Cyclone® IV devices | "PPDS" | 
| PPDS_E_3R | Cyclone® IV devices, Intel® MAX® 10 devices | "PPDS_E_3R" | 
| SLVS | Cyclone® V devices | "SLVS" | 
| mini-LVDS_E_1R | Cyclone® V devices,Arria® V devices | "mini-LVDS_E_1R" | 
| mini-LVDS_E_3R | Cyclone® V devices,Arria® V devices | "mini-LVDS_E_3R | 
| CML | Intel® Arria® 10 devices | "CURRENT MODE LOGIC (CML)" | 
| 1.5-V Schmitt Trigger Input | Intel® MAX® 10 devices | "1.5V Schmitt Trigger Input" | 
| 1.8-V Schmitt Trigger Input | Intel® MAX® 10 devices | "1.8V Schmitt Trigger Input" | 
| HiSpi | Cyclone® V devices, Intel® MAX® 10 devices | "HISPI" | 
| Sub-LVDS | Cyclone® IV devices, Intel® MAX® 10 devices | "SUB-LVDS" | 
| TMDS | Intel® MAX® 10 devices | TMDS |