Intel Agilex User Manual page 22

Table 6. OCT Schemes Supported in Intel Agilex Devices
Direction
Output
Input
Bidirectional
R OCT
S
The Intel Agilex devices support R
and voltage-referenced I/O standards.
OCT Scheme
R without calibration
S
R with calibration
S
Figure 11. R OCT Without Calibration
S
This figure shows the R
® ™
Intel Agilex General Purpose I/O and LVDS SERDES User Guide
22
OCT with and without calibration for single-ended
S
• Only supported on output buffer.
• Driver-impedance matching provides the I/O driver with controlled output
impedance that closely matches the impedance of the transmission line.
• The OCT calibration circuit uses the impedance of the external resistor that is
connected to the RZQ pin as reference. The impedance of the I/O buffer is
continuously altered until the target impedance is achieved during OCT
calibration. The targeted impedance is achieved when the impedance of I/O
buffer reaches a predetermined ratio to the reference resistance.
• Calibration occurs at the end of device configuration. When the calibration
circuit finds the correct impedance, the circuit powers down and stops
changing the characteristics of the drivers.
• You may trigger re-calibration during user-mode.
as the intrinsic impedance of the output transistors.
S
Driver
Series Termination
V
CCIO
R
S
R
S
GND
3. Intel Agilex I/O Termination
OCT Schemes
R OCT with calibration
S
R OCT without calibration
S
R OCT with calibration
T
Dynamic R and R OCT
S T
Description
Receiving
Device
Z = 50 Ω
0
UG-20214 | 2019.04.02
Send Feedback