Introduction

FPGA IO Standards Reference covers all the IO standards supported in Altium Designer. The device support tables given with individual IO standard provide information about the value for the standard when used as a constraints attribute.

IO Standards

The available IO Standards are listed as follows:

AGP1x	AGP2x	BLVDS25	COMPACTPCI_3
CTT	DHSTL18I	DHSTL18II	DHSTL18II_DCI
DHSTL18III	DHSTLI	DHSTLII	DHSTLII_DCI
DHSTLIII	DSSTL2I	DSSTL2II	DSSTL2II_DCI
DSSTL3I	DSSTL3II	DSSTL18I	DSSTL18II
DSSTL18II_DCI	FPGA_DRIVE	FPGA_SLEW	GTL
GTL_DCI	GTLP	GTLP_DCI	HSTL_12
HSTLI	HSTLI_18	HSTLI_18_DCI	HSTLI_DCI
HSTLII	HSTLII_18	HSTLII_18_DCI	HSTLII_DCI
HSTLIII	HSTLIII_18	HSTLIII_18_DCI	HSTLIII_DCI
HSTLIV	HSTLIV_18	HSTLIV_18_DCI	HSTLIV_DCI
HTT	LDT	LDT_DT	LVCMOS5
LVCMOS12	LVCMOS15	LVCMOS15_DCI	LVCMOS15_DCI_DV2
LVCMOS18	LVCMOS18_DCI	LVCMOS18_DCI_DV2	LVCMOS25
LVCMOS25_DCI	LVCMOS25_DCI_DV2	LVCMOS33	LVCMOS33_DCI
LVCMOS33_DCI_DV2	LVDS	LVDS25_DCI	LVDS33
LVDS33_DCI	LVDS_DT	LVDSEXT25	LVDSEXT25_DCI
LVDSEXT25_DT	LVDSEXT33	LVDSEXT33_DCI	LVPECL
LVPECL25	LVTTL15	LVTTL18	LVTTL25
LVTTL33	MiniLVDS25	PCI33_3	PCI33_5
PCI66	PCIX_3	PCML	PCML15
RSDS25	SSTL2I	SSTL2I_DCI	SSTL2II
SSTL2II_DCI	SSTL3I	SSTL3I_DCI	SSTL3II
SSTL3II_DCI	SSTL18I	SSTL18I_DCI	SSTL18II
SSTL18II_DCI	TTL	ULVDS25	ULVDS25_DT

AGP1X

Accelerated Graphics Port 1x

AGP2X

Accelerated Graphics Port 2x

BLVDS25

Bus Low Voltage Differential Signaling (2.5 Volts)

COMPACTPCI_3

Compact Peripheral Component Interconnect (3.3 Volts)

CTT

Center Tap Terminated

DHSTL18I

Differential High-Speed Transceiver Logic (1.8 Volts) Class I

DHSTL18II

Differential High-Speed Transceiver Logic (1.8 Volts) Class II

DHSTL18II_DCI

Differential High-Speed Transceiver Logic (1.8 Volts) Class II with Digitally Controlled Impedance technology

DHSTL18III

Differential High-Speed Transceiver Logic (1.8 Volts) Class III

DHSTLI

Differential High-Speed Transceiver Logic Class I

DHSTLII

Differential High-Speed Transceiver Logic Class II

DHSTLII_DCI

Differential High-Speed Transceiver Logic Class II with Digitally Controlled Impedance technology

DHSTLIII

Differential High-Speed Transceiver Logic Class III

DSSTL2I

Differential Stub Series Terminated Logic (2.5 Volts) Class I

DSSTL2II

Differential Stub Series Terminated Logic (2.5 Volts) Class II

DSSTL2II_DCI

Differential Stub Series Terminated Logic (2.5 Volts) Class II with Digitally Controlled Impedance technology

DSSTL3I

Differential Stub Series Terminated Logic (3.3 Volts) Class I

DSSTL3II

Differential Stub Series Terminated Logic (3.3 Volts) Class II

DSSTL18I

Differential Stub Series Terminated Logic (1.8 Volts) Class I

DSSTL18II

Differential Stub Series Terminated Logic (1.8 Volts) Class II

DSSTL18II_DCI

Differential Stub Series Terminated Logic (1.8 Volts) Class II with Digitally Controlled Impedance technology

FPGA_DRIVE

FPGA Drive Strength

FPGA_SLEW

FPGA Slew Rate

GTL

Gunning Transceiver Logic

GTL_DCI

Gunning Transceiver Logic with Digitally Controlled Impedance

GTLP

Gunning Transceiver Logic Plus

GTLP_DCI

Gunning Transceiver Logic Plus with Digitally Controlled Impedance

HSTL_12

High-Speed Transceiver Logic (1.2 Volts)

HSTLI

High-Speed Transceiver Logic Class I

HSTLI_18

High-Speed Transceiver Logic (1.8 Volts) Class I

HSTLI_18_DCI

High-Speed Transceiver Logic (1.8 Volts) Class I with Digitally Controlled Impedance technology

HSTLI_DCI

High-Speed Transceiver Logic Class I with Digitally Controlled Impedance technology

HSTLII

High-Speed Transceiver Logic Class II

HSTLII_18

High-Speed Transceiver Logic (1.8 Volts) Class II

HSTLII_18_DCI

High-Speed Transceiver Logic (1.8 Volts) Class II with Digitally Controlled Impedance technology

HSTLII_DCI

High-Speed Transceiver Logic Class II with Digitally Controlled Impedance technology

HSTLIII

High-Speed Transceiver Logic Class III

HSTLIII_18

High-Speed Transceiver Logic (1.8 Volts) Class III

HSTLIII_18_DCI

High-Speed Transceiver Logic (1.8 Volts) Class III with Digitally Controlled Impedance technology

HSTLIII_DCI

High-Speed Transceiver Logic Class III with Digitally Controlled Impedance technology

HSTLIV

High-Speed Transceiver Logic Class IV

HSTLIV_18

High-Speed Transceiver Logic (1.8 Volts) Class IV

HSTLIV_18_DCI

High-Speed Transceiver Logic (1.8 Volts) Class IV with Digitally Controlled Impedance technology

HSTLIV_DCI

High-Speed Transceiver Logic Class IV with Digitally Controlled Impedance technology

HTT

HyperTransport Technology

LDT

Lightning Data Transport

LDT_DT

Lightning Data Transport with Differential Termination

LVCMOS5

Low-Voltage Complementary Metal-Oxide Semiconductor (5 Volts)

LVCMOS12

Low-Voltage Complementary Metal-Oxide Semiconductor (1.2 Volts)

LVCMOS15

Low-Voltage Complementary Metal-Oxide Semiconductor (1.5 Volts)

LVCMOS15_DCI

Low-Voltage Complementary Metal-Oxide Semiconductor (1.5 Volts) with Digitally Controlled Impedance technology

LVCMOS15_DCI_DV2

Low-Voltage Complementary Metal-Oxide Semiconductor (1.5 Volts) with Digitally Controlled Impedance technology supporting controlled impedance drivers with half-impedance

LVCMOS18

Low-Voltage Complementary Metal-Oxide Semiconductor (1.8 Volts)

LVCMOS18_DCI

Low-Voltage Complementary Metal-Oxide Semiconductor (1.8 Volts) with Digitally Controlled Impedance technology

LVCMOS18_DCI_DV2

Low-Voltage Complementary Metal-Oxide Semiconductor (1.8 Volts) with Digitally Controlled Impedance technology supporting controlled impedance drivers with half-impedance

LVCMOS25

Low-Voltage Complementary Metal-Oxide Semiconductor (2.5 Volts)

LVCMOS25_DCI

Low-Voltage Complementary Metal-Oxide Semiconductor (2.5 Volts) with Digitally Controlled Impedance technology

LVCMOS25_DCI_DV2

Low-Voltage Complementary Metal-Oxide Semiconductor (2.5 Volts) with Digitally Controlled Impedance technology supporting controlled impedance drivers with half-impedance

LVCMOS33

Low-Voltage Complementary Metal-Oxide Semiconductor (3.3 Volts)

LVCMOS33_DCI

Low-Voltage Complementary Metal-Oxide Semiconductor (3.3 Volts) with Digitally Controlled Impedance technology

LVCMOS33_DCI_DV2

Low-Voltage Complementary Metal-Oxide Semiconductor (3.3 Volts) with Digitally Controlled Impedance technology supporting controlled impedance drivers with half-impedance

LVDS

Low Voltage Differential Signaling

LVDS25_DCI

Low Voltage Differential Signaling (2.5 Volts) with Digitally Controlled Impedance technology

LVDS33

Low Voltage Differential Signaling (3.3 Volts)

LVDS33_DCI

Low Voltage Differential Signaling (3.3 Volts) with Digitally Controlled Impedance technology

LVDS_DT

Low Voltage Differential Signaling with Differential Termination

LVDSEXT25

Extended Low Voltage Differential Signaling (2.5 Volts)

LVDSEXT25_DCI

Extended Low Voltage Differential Signaling (2.5 Volts) with Digitally Controlled Impedance technology

LVDSEXT25_DT

Extended Low Voltage Differential Signaling (2.5 Volts) with Differential Termination

LVDSEXT33

Extended Low Voltage Differential Signaling (3.3 Volts)

LVDSEXT33_DCI

Extended Low Voltage Differential Signaling (3.3 Volts) with Digitally Controlled Impedance technology

LVPECL

Low-Voltage Positive Emitter-Coupled Logic

LVPECL25

Low-Voltage Positive Emitter-Coupled Logic (2.5 Volts)

LVTTL15

Low-Voltage Transistor-Transistor Logic (1.5 Volts)

LVTTL18

Low-Voltage Transistor-Transistor Logic (1.8 Volts)

LVTTL25

Low-Voltage Transistor-Transistor Logic (2.5 Volts)

LVTTL33

Low-Voltage Transistor-Transistor Logic (3.3 Volts)

MINILVDS25

Mini Low Voltage Differential Signaling with Differential Termination (2.5 Volts)

PCI33_3

Peripheral Component Interconnect (33 MHz, 3.3 Volts)

PCI33_5

Peripheral Component Interconnect (33 MHz, 5 Volts)

PCI66

Peripheral Component Interconnect (66 MHz, 3.3 Volts)

PCIX_3

Peripheral Component Interconnect
- X (3.3 Volts)

PCML

Pseudo Current Mode Logic

PCML15

Pseudo Current Mode Logic (1.5 Volts)

RSDS25

Reduced Swing Differential Signaling (2.5 Volts)

SSTL2I

Stub Series Terminated Logic (2.5 Volts) Class I

SSTL2I_DCI

Stub Series Terminated Logic (2.5 Volts) Class I with Digitally Controlled Impedance technology

SSTL2II

Stub Series Terminated Logic (2.5 Volts) Class II

SSTL2II_DCI

Stub Series Terminated Logic (2.5 Volts) Class II with Digitally Controlled Impedance technology

SSTL3I

Stub Series Terminated Logic (3.3 Volts) Class I

SSTL3I_DCI

Stub Series Terminated Logic (3.3 Volts) Class I with Digitally Controlled Impedance technology

SSTL3II

Stub Series Terminated Logic (3.3 Volts) Class II

SSTL3II_DCI

Stub Series Terminated Logic (3.3 Volts) Class II with Digitally Controlled Impedance technology

SSTL18I

Stub Series Terminated Logic (1.8 Volts) Class I

SSTL18I_DCI

Stub Series Terminated Logic (1.8 Volts) Class I with Digitally Controlled Impedance technology

SSTL18II

Stub Series Terminated Logic (1.8 Volts) Class II

SSTL18II_DCI

Stub Series Terminated Logic (1.8 Volts) Class II with Digitally Controlled Impedance technology

TTL

Transistor-Transistor Logic

ULVDS25

Ultra Low Voltage Differential Signaling with Differential Termination (2.5 Volts)

ULVDS25_DT

Ultra Low Voltage Differential Signaling with Differential Termination (2.5 Volts) with Differential Termination