Cyclone® 10 GX Core Fabric and General Purpose I/Os Handbook

ID 683775
Date 7/08/2024
Public
Document Table of Contents

5.5.4.1. RS OCT without Calibration in Cyclone® 10 GX Devices

The Cyclone® 10 GX devices support RS OCT for single-ended and voltage-referenced I/O standards. RS OCT without calibration is supported on output only.

Table 44.  Selectable I/O Standards for RS OCT Without CalibrationThis table lists the output termination settings for uncalibrated OCT on different I/O standards.
I/O Standard Uncalibrated OCT (Output)
RS (Ω)
3.0 V LVTTL/3.0 V LVCMOS 25/50
2.5 V LVCMOS 25/50
1.8 V LVCMOS 25/50
1.5 V LVCMOS 25/50
1.2 V LVCMOS 25/50
SSTL-18 Class I 50
SSTL-18 Class II 25
SSTL-15 Class I 50
SSTL-15 Class II 25
SSTL-15 34, 40
SSTL-135 34, 40
SSTL-125 34, 40
SSTL-12 40, 60, 120, 240
POD12 34, 40, 48, 60
1.8 V HSTL Class I 50
1.8 V HSTL Class II 25
1.5 V HSTL Class I 50
1.5 V HSTL Class II 25
1.2 V HSTL Class I 50
1.2 V HSTL Class II 25
HSUL-12 34.3, 40, 48, 60, 80
Differential SSTL-18 Class I 50
Differential SSTL-18 Class II 25
Differential SSTL-15 Class I 50
Differential SSTL-15 Class II 25
Differential SSTL-15 34, 40
Differential SSTL-135 34, 40
Differential SSTL-125 34, 40
Differential SSTL-12 40, 60, 120, 240
Differential POD12 34, 40, 48, 60
Differential 1.8 V HSTL Class I 50
Differential 1.8 V HSTL Class II 25
Differential 1.5 V HSTL Class I 50
Differential 1.5 V HSTL Class II 25
Differential 1.2 V HSTL Class I 50
Differential 1.2 V HSTL Class II 25
Differential HSUL-12 34.3, 40, 48, 60, 80

Driver-impedance matching provides the I/O driver with controlled output impedance that closely matches the impedance of the transmission line. As a result, you can significantly reduce signal reflections on PCB traces.

If you select matching impedance, current strength is no longer selectable.

Figure 74. RS OCT Without CalibrationThis figure shows the RS as the intrinsic impedance of the output transistors.